/* 
    DHTML PNG Snowstorm! OO-style Jascript-based Snow effect 
    -------------------------------------------------------- 
    Version 1.2.20041121a 
    Dependencies: GIF/PNG images (0 through 4.gif/png) 
    Code by Scott Schiller - www.schillmania.com 
    -------------------------------------------------------- 
    Description: 
    
    Initializes after body onload() by default (via addEventHandler() call at bottom.) 
    
    Properties: 
    
    usePNG 
    --------------- 
    Enables PNG images if supported ("false" disables all PNG usage) 
    
    flakeTypes 
    --------------- 
    Sets the range of flake images to use (eg. a value of 5 
    will use images ranging from 0.png to 4.png.) 
    
    flakesMax 
    --------------- 
    Sets the maximum number of snowflakes that can exist on 
    the screen at any given time. 
     
    flakesMaxActive 
    --------------- 
    Sets the limit of "falling" snowflakes (ie. moving, thus 
    considered to be "active".) 
    
    vMax 
    --------------- 
    Defines the maximum X and Y velocities for the storm. 
    A range up to this value is selected at random. 
    
    flakeWidth 
    --------------- 
    The width (in pixels) of each snowflake image. 
    
    flakeHeight 
    --------------- 
    Height (pixels) of each snowflake image. 
     
    flakeBottom 
    --------------- 
    Limits the "bottom" coordinate of the snow. 
    
    snowCollect 
    --------------- 
    Enables snow to pile up (slowly) at bottom of window. 
    Can be very CPU/resource-intensive over time. 

*/ 

var snowStorm = null; 

function SnowStorm() { 
   var s = this; 
   var storm = this; 
   this.timers = []; 
   this.flakes = []; 
   this.disabled = false; 
   this.terrain = []; 

   // User-configurable variables 
   // --------------------------- 

   var usePNG = true; 
   var imagePath = './snow/'; // relative path to snow images 
   var flakeTypes = 6; 
   this.flakesMax = 128; 
   var flakesMaxActive = 64; 
   var vMax = 2.5; 
   var flakeWidth = 5; 
   var flakeHeight = 5; 
   var flakeBottom = 0; // Integer for fixed bottom, 0 or null for "full-screen" snow effect 
   var snowCollect = false; 
   var showStatus = true; 

   // --- End of user section --- 

   var isIE = (navigator.appName.toLowerCase().indexOf('internet explorer')+1); 
   var isWin9X = (navigator.appVersion.toLowerCase().indexOf('windows 98')+1); 
   var isOpera = (navigator.userAgent.toLowerCase().indexOf('opera ')+1 || navigator.userAgent.toLowerCase().indexOf('opera/')+1); 
   if (isOpera) isIE = false; // Opera (which is sneaky, pretending to be IE by default) 
   var screenX = null; 
   var screenY = null; 
   var scrollY = null; 
   var vRndX = null; 
   var vRndY = null; 

   function rnd(n,min) { 
     if (isNaN(min)) min = 0; 
     return (Math.random()*n)+min; 
   } 

   this.randomizeWind = function() { 
     vRndX = plusMinus(rnd(vMax,0.2)); 
     vRndY = rnd(vMax,0.2); 
     if (this.flakes) { 
       for (var i=0; i<this.flakes.length; i++) { 
         if (this.flakes[i].active) this.flakes[i].setVelocities(); 
       } 
     } 
   } 

   function plusMinus(n) { 
     return (parseInt(rnd(2))==1?n*-1:n); 
   } 

   this.resizeHandler = function() { 
     if (window.innerWidth || window.innerHeight) { 
       screenX = window.innerWidth-(!isIE?24:2); 
       screenY = (flakeBottom?flakeBottom:window.innerHeight); 
     } else { 
       screenX = (document.documentElement.clientWidth||document.body.clientWidth||document.body.scrollWidth)-(!isIE?8:0); 
       screenY = flakeBottom?flakeBottom:(document.documentElement.clientHeight||document.body.clientHeight||document.body.scrollHeight); 
     } 
     s.scrollHandler(); 
   } 

   this.scrollHandler = function() { 
     // "attach" snowflakes to bottom of window if no absolute bottom value was given 
     scrollY = (flakeBottom?0:parseInt(window.scrollY||document.documentElement.scrollTop||document.body.scrollTop)); 
     if (isNaN(scrollY)) scrollY = 0; // Netscape 6 scroll fix 
     if (!flakeBottom && s.flakes) { 
       for (var i=0; i<s.flakes.length; i++) { 
         if (s.flakes[i].active == 0) s.flakes[i].stick(); 
       } 
     } 
   } 

   this.freeze = function() { 
     // pause animation 
     if (!s.disabled) { 
       s.disabled = 1; 
     } else { 
       return false; 
     } 
     if (!isWin9X) { 
       clearInterval(s.timers); 
     } else { 
       for (var i=0; i<s.timers.length; i++) { 
         clearInterval(s.timers[i]); 
       } 
     } 
   } 

   this.resume = function() { 
     if (s.disabled) { 
        s.disabled = 0; 
     } else { 
       return false; 
     } 
     s.timerInit(); 
   } 

   this.stop = function() { 
     this.freeze(); 
     for (var i=0; i<this.flakes.length; i++) { 
       this.flakes[i].o.style.display = 'none'; 
     } 
     removeEventHandler(window,'scroll',this.scrollHandler,false); 
     removeEventHandler(window,'resize',this.resizeHandler,false); 
   } 

   this.SnowFlake = function(parent,type,x,y) { 
     var s = this; 
     var storm = parent; 
     this.type = type; 
     this.x = x||parseInt(rnd(screenX-12)); 
     this.y = (!isNaN(y)?y:-12); 
     this.vX = null; 
     this.vY = null; 
     this.vAmpTypes = [2.0,1.0,1.25,1.0,1.5,1.75]; // "amplification" for vX/vY (based on flake size/type) 
     this.vAmp = this.vAmpTypes[this.type]; 

     this.active = 1; 
     this.o = document.createElement('img'); 
     this.o.style.position = 'absolute'; 
     this.o.style.width = flakeWidth+'px'; 
     this.o.style.height = flakeHeight+'px'; 
     this.o.style.fontSize = '1px'; // so IE keeps proper size 
     this.o.style.zIndex = 2; 
     this.o.src = imagePath+this.type+(pngHandler.supported && usePNG?'.png':'.gif'); 
     document.body.appendChild(this.o); 
     if (pngHandler.supported && usePNG) pngHandler.transform(this.o); 

     this.refresh = function() { 
       this.o.style.left = this.x+'px'; 
       this.o.style.top = this.y+'px'; 
     } 

     this.stick = function() { 
       s.o.style.top = (screenY+scrollY-flakeHeight-storm.terrain[Math.floor(this.x)])+'px'; 
       // called after relative left has been called 
     } 

     this.vCheck = function() { 
       if (this.vX>=0 && this.vX<0.2) { 
         this.vX = 0.2; 
       } else if (this.vX<0 && this.vX>-0.2) { 
         this.vX = -0.2; 
       } 
       if (this.vY>=0 && this.vY<0.2) { 
         this.vY = 0.2; 
       } 
     } 

     this.move = function() { 
       this.x += this.vX; 
       this.y += (this.vY*this.vAmp); 
       this.refresh(); 

       if (this.vX && screenX-this.x<flakeWidth+this.vX) { // X-axis scroll check 
         this.x = 0; 
       } else if (this.vX<0 && this.x<0-flakeWidth) { 
         this.x = screenX-flakeWidth; // flakeWidth; 
       } 
       var yDiff = screenY+scrollY-this.y-storm.terrain[Math.floor(this.x)]; 
       if (yDiff<flakeHeight) { 
         this.active = 0; 
         if (snowCollect) { 
           var height = [0.75,1.5,0.75]; 
           for (var i=0; i<2; i++) { 
             storm.terrain[Math.floor(this.x)+i+2] += height[i]; 
           } 
         } 
         this.o.style.left = ((this.x-(!isIE?flakeWidth:0))/screenX*100)+'%'; // set "relative" left (change with resize) 
         if (!flakeBottom) { 
           this.stick(); 
         } 
       } 
     } 

     this.animate = function() { 
       // main animation loop 
       // move, check status, die etc. 
       this.move(); 
     } 

     this.setVelocities = function() { 
       this.vX = vRndX+rnd(vMax*0.12,0.1); 
       this.vY = vRndY+rnd(vMax*0.12,0.1); 
     } 

     this.recycle = function() { 
       this.setVelocities(); 
       this.vCheck(); 
       this.x = parseInt(rnd(screenX-flakeWidth-1)); 
       this.y = parseInt(rnd(640)*-1)-flakeHeight; 
       this.active = 1; 
     } 

     this.recycle(); // set up x/y coords etc. 
     this.refresh(); 

   } 

   this.snow = function() { 
     var active = 0; 
     var used = 0; 
     var waiting = 0; 
     for (var i=this.flakes.length-1; i>0; i--) { 
       if (this.flakes[i].active == 1) { 
         this.flakes[i].animate(); 
         active++; 
       } else if (this.flakes[i].active == 0) { 
         used++; 
       } else { 
         waiting++; 
       } 
     } 
     if (snowCollect && !waiting) { // !active && !waiting 
       // create another batch of snow 
       this.createSnow(flakesMaxActive,true); 
     } 
     if (active<flakesMaxActive) { 
       with (this.flakes[parseInt(rnd(this.flakes.length))]) { 
         if (!snowCollect && active == 0) { 
           recycle(); 
         } else if (active == -1) { 
           active = 1; 
         } 
       } 
     } 
   } 

   this.createSnow = function(limit,allowInactive) { 
     if (showStatus) window.status = 'Creating snow...'; 
     for (var i=0; i<limit; i++) { 
       this.flakes[this.flakes.length] = new this.SnowFlake(this,parseInt(rnd(flakeTypes))); 
       if (allowInactive || i>flakesMaxActive) this.flakes[this.flakes.length-1].active = -1; 
     } 
     if (showStatus) window.status = ''; 
   } 

   this.timerInit = function() { 
     this.timers = (!isWin9X?setInterval("snowStorm.snow()",20):[setInterval("snowStorm.snow()",75),setInterval("snowStorm.snow()",25)]); 
   } 

   this.init = function() { 
     for (var i=0; i<8192; i++) { 
       this.terrain[i] = 0; 
     } 
     this.randomizeWind(); 
     this.createSnow(snowCollect?flakesMaxActive:flakesMaxActive*2); // create initial batch 
     addEventHandler(window,'resize',this.resizeHandler,false); 
     addEventHandler(window,'scroll',this.scrollHandler,false); 
     // addEventHandler(window,'scroll',this.resume,false); // scroll does not cause window focus. (odd) 
     // addEventHandler(window,'blur',this.freeze,false); 
     // addEventHandler(window,'focus',this.resume,false); 
     this.timerInit(); 
   } 

   this.resizeHandler(); // get screen coordinates 

   if (screenX && screenY && !this.disabled) { 
     this.init(); 
   } 

} 

function snowStormInit() { 
   setTimeout("snowStorm = new SnowStorm()",500); 
} 

// Generic addEventHandler() wrapper 
// --------------------------------- 
// A generic interface for adding DOM event handlers 
// Version 1.2.20040404 
// 
// Code by Scott Schiller | schillmania.com 
// 
// Revision history: 
// --------------------------------- 
// v1.1.20031218: initial deploy 
// v1.2.20040404: added post-load event check 

var addEventHandler = null; 
var removeEventHandler = null; 

function postLoadEvent(eventType) { 
   // test for adding an event to the body (which has already loaded) - if so, fire immediately 
   return ((eventType.toLowerCase().indexOf('load')>=0) && document.body); 
} 

function addEventHandlerDOM(o,eventType,eventHandler,eventBubble) { 
   if (!postLoadEvent(eventType)) { 
     o.addEventListener(eventType,eventHandler,eventBubble); 
   } else { 
     eventHandler(); 
   } 
} 

function removeEventHandlerDOM(o,eventType,eventHandler,eventBubble) { 
   o.removeEventListener(eventType,eventHandler,eventBubble); 
} 
    
function addEventHandlerIE(o,eventType,eventHandler) { // IE workaround 
   if (!eventType.indexOf('on')+1) eventType = 'on'+eventType; 
   if (!postLoadEvent(eventType)) { 
     o.attachEvent(eventType,eventHandler); // Note addition of "on" to event type 
   } else { 
     eventHandler(); 
   } 
} 
    
function removeEventHandlerIE(o,eventType,eventHandler) { 
   if (!eventType.indexOf('on')+1) eventType = 'on'+eventType; 
   o.detachEvent(eventType,eventHandler); 
} 

function addEventHandlerOpera(o,eventType,eventHandler,eventBubble) { 
   if (!postLoadEvent(eventType)) { 
     (o==window?document:o).addEventListener(eventType,eventHandler,eventBubble); 
   } else { 
     eventHandler(); 
   } 
} 

function removeEventHandlerOpera(o,eventType,eventHandler,eventBubble) { 
   (o==window?document:o).removeEventListener(eventType,eventHandler,eventBubble); 
} 

if (navigator.userAgent.toLowerCase().indexOf('opera ')+1 || navigator.userAgent.toLowerCase().indexOf('opera/')+1) { 
   // opera is dumb at times. 
   addEventHandler = addEventHandlerOpera; 
   removeEventHandler = removeEventHandlerOpera; 
} else if (document.addEventListener) { // DOM event handler method 
   addEventHandler = addEventHandlerDOM; 
   removeEventHandler = removeEventHandlerDOM; 
} else if (document.attachEvent) { // IE event handler method 
   addEventHandler = addEventHandlerIE; 
   removeEventHandler = removeEventHandlerIE; 
} else { // Neither "DOM level 2" (?) methods supported 
   addEventHandler = function(o,eventType,eventHandler,eventBubble) { 
     o['on'+eventType] = eventHandler; 
     // Multiple events could be added here via array etc. 
   } 
   removeEventHandler = function(o,eventType,eventHandler,eventBubble) {} 
} 

// Safari 1.0 does not support window.scroll events - apparently netscape 6.0/6.2 and mozilla 1.4 also. 
// Refer to events support table at http://www.quirksmode.org/js/events_compinfo.html 

// -- end addEventHandler definition -- 

/* 
    PNGHandler: Object-Oriented Javascript-based PNG wrapper 
    -------------------------------------------------------- 
    Version 1.2.20040803 
    Code by Scott Schiller - www.schillmania.com 
    -------------------------------------------------------- 
    Description: 
    Provides gracefully-degrading PNG functionality where 
    PNG is supported natively or via filters (Damn you, IE!) 
    Should work with PNGs as images and DIV background images. 
    -------------------------------------------------------- 
    Revision history 
    -------------------------------------------------------- 
    1.2 
    - Added refresh() for changing PNG images under IE 
    - Class extension: "scale" causes PNG to scale under IE 
    -------------------------------------------------------- 
    Known bugs 
    -------------------------------------------------------- 
    - ie:mac doesn't support PNG background images. 
    - Safari doesn't support currentStyle() - can't parse BG 
      via CSS (ie. for a DIV with a PNG background by class) 

*/ 

function PNGHandler() { 
   var self = this; 

   this.na = navigator.appName.toLowerCase(); 
   this.nv = navigator.appVersion.toLowerCase(); 
   this.isIE = this.na.indexOf('internet explorer')+1?1:0; 
   this.isWin = this.nv.indexOf('windows')+1?1:0; 
   this.isIEMac = (this.isIE&&!this.isWin); 
   this.isIEWin = (this.isIE&&this.isWin); 
   this.ver = this.isIE?parseFloat(this.nv.split('msie ')[1]):parseFloat(this.nv); 
   this.isMac = this.nv.indexOf('mac')+1?1:0; 
   this.isOpera = (navigator.userAgent.toLowerCase().indexOf('opera ')+1 || navigator.userAgent.toLowerCase().indexOf('opera/')+1);
   if (this.isOpera) this.isIE = false; // Opera filter catch (which is sneaky, pretending to be IE by default) 
   this.filterID = 'DXImageTransform.Microsoft.AlphaImageLoader'; 
   this.supported = false; 
   this.transform = self.doNothing; 

   this.filterMethod = function(o) { 
     // IE 5.5+ proprietary filter garbage (boo!) 
     // Create new element based on old one. Doesn't seem to render properly otherwise (due to filter?) 
     // use DOM "currentStyle" method, so rules inherited via CSS are picked up. 
     if (o.nodeName != 'IMG') { 
       var b = o.currentStyle.backgroundImage.toString(); // parse out background image URL 
       o.style.backgroundImage = 'none'; 
       // Parse out background image URL from currentStyle. 
       var i1 = b.indexOf('url("')+5; 
       var newSrc = b.substr(i1,b.length-i1-2).replace('.gif','.png'); // find first instance of ") after (", chop from string 
       o.style.writingMode = 'lr-tb'; // Has to be applied so filter "has layout" and is displayed. Seriously. Refer to http://msdn.microsoft.com/workshop/author/filter/reference/filters/alphaimageloader.asp?frame=true 
       o.style.filter = "progid:"+self.filterID+"(src='"+newSrc+"',sizingMethod='"+(o.className.indexOf('scale')+1?'scale':'crop')+"')"; 
     } else if (o.nodeName == 'IMG') { 
       var newSrc = o.getAttribute('src').replace('.gif','.png'); 
       // apply filter 
       o.src = 'image/none.gif'; // get rid of image 
       o.style.filter = "progid:"+self.filterID+"(src='"+newSrc+"',sizingMethod="+(o.className.indexOf('scale')+1?'scale':'crop')+"')"; 
       o.style.writingMode = 'lr-tb'; // Has to be applied so filter "has layout" and is displayed. Seriously. Refer to http://msdn.microsoft.com/workshop/author/filter/reference/filters/alphaimageloader.asp?frame=true 
     } 
   } 

   this.pngMethod = function(o) { 
     // Native transparency support. Easy to implement. (woo!) 
     bgImage = this.getBackgroundImage(o); 
     if (bgImage) { 
       // set background image, replacing .gif 
       o.style.backgroundImage = 'url('+bgImage.replace('.gif','.png')+')'; 
     } else if (o.nodeName == 'IMG') { 
       o.src = o.src.replace('.gif','.png'); 
     } else if (!bgImage) { 
       // no background image 
     } 
   } 

   this.getBackgroundImage = function(o) { 
     var b, i1; // background-related variables 
     var bgUrl = null; 
     if (o.nodeName != 'IMG' && !(this.isIE && this.isMac)) { // ie:mac PNG support broken for DIVs with PNG backgrounds 
       if (document.defaultView) { 
         if (document.defaultView.getComputedStyle) { 
           b = document.defaultView.getComputedStyle(o,'').getPropertyValue('background-image'); 
           i1 = b.indexOf('url(')+4; 
           bgUrl = b.substr(i1,b.length-i1-1); 
         } else { 
           // no computed style 
           return false; 
         } 
       } else { 
         // no default view 
         return false; 
       } 
     } 
     return bgUrl; 
   } 

   this.doNothing = function() {} 
    
   this.supportTest = function() { 
     // Determine method to use. 
     // IE 5.5+/win32: filter 

     if (this.isIE && this.isWin && this.ver >= 5.5) { 
       // IE proprietary filter method (via DXFilter) 
       self.transform = self.filterMethod; 
     } else if (!this.isIE && this.ver < 5) { 
       // No PNG support or broken support 
       // Leave existing content as-is 
       self.transform = null; 
       return false; 
     } else if (!this.isIE && this.ver >= 5 || (this.isIE && this.isMac && this.ver >= 5)) { // version 5+ browser (not IE), or IE:mac 5+ 
       self.transform = self.pngMethod; 
     } else { 
       // Presumably no PNG support. GIF used instead. 
       self.transform = null; 
       return false; 
     } 
     return true; 
   } 

   this.init = function() { 
     this.supported = this.supportTest(); 
   } 

} 

function getElementsByClassName(className,oParent) { 
   var doc = (oParent||document); 
   var matches = []; 
   var nodes = doc.all||doc.getElementsByTagName('*'); 
   for (var i=0; i<nodes.length; i++) { 
     if (nodes[i].className == className || nodes[i].className.indexOf(className)+1 || nodes[i].className.indexOf(className+' ')+1 || nodes[i].className.indexOf(' '+className)+1) { 
       matches[matches.length] = nodes[i]; 
     } 
   } 
   return matches; // kids, don't play with fire. <img rel="usm" src="http://megasoft.3dn.ru/emoticons/Mirktelejimas.gif" border="0" align="absmiddle" alt=";)"> 
} 

// Instantiate and initialize PNG Handler 

var pngHandler = new PNGHandler(); 

pngHandler.init(); 

addEventHandler(window,'load',snowStormInit,false);