var mrMac = (navigator.userAgent.indexOf('Mac') != -1);

var currentPhoto = 0;
var secondPhoto = 1;

var currentOpacity = new Array();
var imageArray = new Array(
  "images/common/courses/courses.gif",
   "images/common/courses/courses1.gif",
     "images/common/courses/courses2.gif",
       "images/common/courses/courses3.gif",
         "images/common/courses/courses5.gif",
           "images/common/courses/courses6.gif",
             "images/common/courses/courses7.gif",
               "images/common/courses/courses8.gif",
                 "images/common/courses/courses9.gif",
                   "images/common/courses/courses10.gif",
                     "images/common/courses/courses11.gif",
                       "images/common/courses/courses12.gif",
                         "images/common/courses/courses13.gif",
                           "images/common/courses/courses14.gif",
                             "images/common/courses/courses15.gif",
                               "images/common/courses/courses16.gif",
                                 "images/common/courses/courses17.gif",
                                   "images/common/courses/courses18.gif",
                                     "images/common/courses/courses19.gif",
                                       "images/common/courses/courses20.gif",
                                         "images/common/courses/courses21.gif"
			);

var FADE_STEP = 8;
var FADE_INTERVAL = 1;

var pause = false;

/*
var ran_unrounded=Math.random()*(imageArray.length-2);
var ran_number=Math.round(ran_unrounded); 

currentPhoto = ran_number;

if((currentPhoto+1) >= imageArray.length)
{
	secondPhoto = 0;
}
else
{
	secondPhoto = currentPhoto + 1;
}
*/

function init() {

	currentOpacity[0]=99;
	for(i=1;i<imageArray.length;i++)currentOpacity[i]=0;
	mHTML="";
	for(i=0;i<imageArray.length;i++)
	{
		if (mrMac)
			mHTML+="<div id=\"photo\" name=\"photo\" class=\"mPhoto\" style=\"display:none;\"><img src=\"" + imageArray[i]  +"\"></div>";
		else
			mHTML+="<div id=\"photo\" name=\"photo\" class=\"mPhoto\" style=\"-moz-opacity:0.0;Filter:Alpha(Opacity=0);-khtml-opacity:0.00;\"><img src=\"" + imageArray[i]  +"\"></div>";
	}

	document.getElementById("mContainer").innerHTML = mHTML;

	
	mInterval = setInterval("crossFade()",FADE_INTERVAL);
}

function crossFade() {
	if(pause)return;
	
	currentOpacity[currentPhoto]-=FADE_STEP;
	currentOpacity[secondPhoto] += FADE_STEP;

	if (!mrMac)
	{
		if(document.all) {
			document.getElementsByName("photo")[currentPhoto].style.filter = "alpha(opacity=" + currentOpacity[currentPhoto] + ")";
			document.getElementsByName("photo")[secondPhoto].style.filter = "alpha(opacity=" + currentOpacity[secondPhoto] + ")";
		} else {
			document.getElementsByName("photo")[currentPhoto].style.MozOpacity = currentOpacity[currentPhoto]/100;
			document.getElementsByName("photo")[secondPhoto].style.MozOpacity = currentOpacity[secondPhoto]/100;
		}
	}
	else
	{
		document.getElementsByName("photo")[currentPhoto].style.display = "none";
		document.getElementsByName("photo")[currentPhoto].style.KhtmlOpacity = currentOpacity[currentPhoto]/100;
				
		document.getElementsByName("photo")[secondPhoto].style.display  = "block";
		document.getElementsByName("photo")[secondPhoto].style.KhtmlOpacity  = currentOpacity[secondPhoto]/100;
	}
	
	if(currentOpacity[secondPhoto]/100>=.98) {
		currentPhoto = secondPhoto;
		secondPhoto++;
		if(secondPhoto == imageArray.length)secondPhoto=0;
		pause = true;
		xInterval = setTimeout("pause=false",4000);
	}
}

function doPause()  {
	if(pause) {
		pause = false;
		document.getElementById("pauseBtn").value = "pause";
	} else {
		pause = true;
		document.getElementById("pauseBtn").value = "play";
	}
}