// JavaScript Document

var fadeimages = new Array();

fadeimages[0]=["Images/header1.jpg", "index.php", "Home - Discrete Dynamical Systems"];
fadeimages[1]=["Images/header2.jpg", "index.php", "Home - Discrete Dynamical Systems"];
fadeimages[2]=["Images/header3.jpg", "index.php", "Home - Discrete Dynamical Systems"];
fadeimages[3]=["Images/header4.jpg", "index.php", "Home - Discrete Dynamical Systems"];

var fadebgcolor="000000";
var fadearray=new Array(); //array to cache fadeshow instances
var fadeclear=new Array(); //array to cache corresponding clearinterval pointers 
var dom=(document.getElementById); //modern dom browsers
var iebrowser=document.all;
 
function fadeshow(theimages, fadewidth, fadeheight, borderwidth, delay, pause, displayorder)
{
	this.pausecheck=pause;
	this.mouseovercheck=0;
	this.delay=delay;
	this.degree=99; //initial oppacity value _%
	this.curimageindex=0;
	this.nextimageindex=1;
	fadearray[fadearray.length]=this;
	this.slideshowid=fadearray.length-1;
	this.canvasbase="canvas"+this.slideshowid;
	this.curcanvas=this.canvasbase+"_0";
	
	if (typeof displayorder!="undefined")
	{
		theimages.sort(function()
		{
			return(0.5 - Math.random());
		});
	}
		
	this.theimages=theimages;
	this.imageborder=parseInt(borderwidth);
	this.postimages=new Array(); //preload images
	
	for (p = 0; p < theimages.length; p++)
	{
		this.postimages[p]=new Image();
		this.postimages[p].src=theimages[p][0];
	}
 
	var fadewidth=fadewidth+this.imageborder*2;
	var fadeheight=fadeheight+this.imageborder*2;
 
	if (iebrowser&&dom||dom) //if IE5+ or modern browsers (ie: Firefox)
		document.write('<div id="master'+this.slideshowid+'" style="position:relative;width:'+fadewidth+'px;height:'+fadeheight+'px;overflow:hidden;"><div id="'+this.canvasbase+'_0" style="position:absolute;width:'+fadewidth+'px;height:'+fadeheight+'px;top:0;left:0;filter:progid:DXImageTransform.Microsoft.alpha(opacity=10);-moz-opacity:10;-khtml-opacity:10;background-color:'+fadebgcolor+'"></div><div id="'+this.canvasbase+'_1" style="position:absolute;width:'+fadewidth+'px;height:'+fadeheight+'px;top:0;left:0;filter:progid:DXImageTransform.Microsoft.alpha(opacity=10);-moz-opacity:10;background-color:'+fadebgcolor+'"></div></div>');
	else
		document.write('<div><img name="defaultslide'+this.slideshowid+'" src="'+this.postimages[0].src+'"></div>');
	 
	if ((iebrowser && dom) || dom) //if IE5+ or modern browsers such as Firefox
		this.startit();
	else
	{
		this.curimageindex++;
		setInterval("fadearray["+this.slideshowid+"].rotateimage()", this.delay);
	}
}

function fadepic(obj)
{
	if (obj.degree<100)
	{
		obj.degree+=5; //picture transition speed
		if (obj.tempobj.filters&&obj.tempobj.filters[0])
		{
			if (typeof obj.tempobj.filters[0].opacity=="number") //if IE6+
				obj.tempobj.filters[0].opacity=obj.degree;
			else //else if IE5.5-
				obj.tempobj.style.filter="alpha(opacity="+obj.degree+")";
		}
		else if (obj.tempobj.style.MozOpacity)
			obj.tempobj.style.MozOpacity=obj.degree/101;
		else if (obj.tempobj.style.KhtmlOpacity)
			obj.tempobj.style.KhtmlOpacity=obj.degree/100;
	}
	else
	{
		clearInterval(fadeclear[obj.slideshowid]);
		
		obj.nextcanvas = ((obj.curcanvas == obj.canvasbase + "_0") ? obj.canvasbase+"_0" : obj.canvasbase+"_1");
		obj.tempobj= (iebrowser ? iebrowser[obj.nextcanvas] : document.getElementById(obj.nextcanvas));
		obj.populateslide(obj.tempobj, obj.nextimageindex);
		obj.nextimageindex = ((obj.nextimageindex < obj.postimages.length - 1) ? obj.nextimageindex + 1 : 0);
		
		setTimeout("fadearray["+obj.slideshowid+"].rotateimage()", obj.delay);
	}
}
 
fadeshow.prototype.populateslide = function(picobj, picindex)
{
	var slideHTML="";
	
	if (this.theimages[picindex][1]!="") //if associated link exists for image
		slideHTML='<a href="'+this.theimages[picindex][1]+'" target="'+this.theimages[picindex][2]+'">';
		
	slideHTML+='<img src="'+this.postimages[picindex].src+'" border="'+this.imageborder+'px">';
	
	if (this.theimages[picindex][1]!="") //if associated link exists for image
		slideHTML+='</a>';
	
	picobj.innerHTML=slideHTML;
};
 
 
fadeshow.prototype.rotateimage = function()
{
	if (this.pausecheck==1) //if pause onMouseover enabled, cache object
		var cacheobj=this;
	
	if (this.mouseovercheck==1)
	{
		setTimeout(function()
			{
				cacheobj.rotateimage();
			}, 100);
	}		
	else if ((iebrowser && dom) || dom)
	{
		this.resetit();
		var crossobj = this.tempobj = (iebrowser ? iebrowser[this.curcanvas] : document.getElementById(this.curcanvas));
		crossobj.style.zIndex++;
		fadeclear[this.slideshowid] = setInterval("fadepic(fadearray["+this.slideshowid+"])",50);
		this.curcanvas = ((this.curcanvas==this.canvasbase+"_0") ? this.canvasbase+"_1" : this.canvasbase+"_0");
	}
	else
	{
		var ns4imgobj=document.images['defaultslide'+this.slideshowid];
		ns4imgobj.src=this.postimages[this.curimageindex].src;
	}
	
	this.curimageindex = ((this.curimageindex < this.postimages.length-1) ? this.curimageindex + 1 : 0);
};
 
fadeshow.prototype.resetit = function()
{
	this.degree=0;
	var crossobj=iebrowser? iebrowser[this.curcanvas] : document.getElementById(this.curcanvas);
	
	if (crossobj.filters&&crossobj.filters[0])
	{
		if (typeof crossobj.filters[0].opacity=="number") //if IE6+
			crossobj.filters(0).opacity=this.degree;
		else //else if IE5.5-
			crossobj.style.filter="alpha(opacity="+this.degree+")";
	}
	else if (crossobj.style.MozOpacity)
		crossobj.style.MozOpacity=this.degree/101;
	else if (crossobj.style.KhtmlOpacity)
		crossobj.style.KhtmlOpacity=obj.degree/100;
};


fadeshow.prototype.startit = function()
{
	var crossobj = (iebrowser ? iebrowser[this.curcanvas] : document.getElementById(this.curcanvas));
	this.populateslide(crossobj, this.curimageindex);
	
	if (this.pausecheck==1)
	{ //IF SLIDESHOW SHOULD PAUSE ONMOUSEOVER
		var cacheobj=this;
		var crossobjcontainer = (iebrowser ? iebrowser["master"+this.slideshowid] : document.getElementById("master"+this.slideshowid));
		
		crossobjcontainer.onmouseover = function()
		{
			cacheobj.mouseovercheck=1;
		};
		
		crossobjcontainer.onmouseout = function()
		{
			cacheobj.mouseovercheck=0;
		};
	}	
	this.rotateimage();
};