var pvData;
var pvPhoto;
var pvPhotoLoader;
var counter = 0;
var pvTimer = false;
var pvImgLoaded = false;
var pvPlay = true;

function changeOpac(opacity, id) {
 var obj;
 obj = document.getElementById(id).style;
 obj.opacity = (opacity / 100); 
 obj.MozOpacity = (opacity / 100); 
 obj.KhtmlOpacity = (opacity / 100); 
 obj.filter = "alpha(opacity=" + opacity + ")"; 
}

function blendimage(divid, imageid, imagefile, millisec) { 
 var speed = Math.round(millisec / 100); 
 var timer = 0; 
 var div = document.getElementById(divid);
 var img = document.getElementById(imageid);
 if (img.src) div.style.backgroundImage = "url(" + img.src + ")";
 changeOpac(0, imageid); 
 img.src = imagefile; 
 for(i = 0; i <= 100; i++)
 {
 setTimeout("changeOpac(" + i + ",'" + imageid + "')",(timer * speed)); 
 timer++; 
 } 
}

function displayPVImg()
{
  blendimage("pv","pvPhoto",pvPhotoLoader.src,1500);
  pvTimer = false;
  pvImgLoaded = false;
  changeImg();
}

function pvTimerReached()
{
 pvTimer = true;
 if (pvImgLoaded && pvPlay) displayPVImg();
}

function onPVload(e)
{
 e = e || window.event;
 var target = e.srcElement || e.target;
 pvImgLoaded = true;
 if (pvTimer && pvPlay) displayPVImg();
}

function changeImg()
{
 var ord = counter++ % pvData.imgs.length;
 pvPhotoLoader.src = pvData.base + "/" + pvData.imgs[ord];
 setTimeout("pvTimerReached()",5000); 
}


function initPV(pvd)
{
 pvData = pvd;
 pvPhoto = document.getElementById("pvPhoto");
 pvPhotoLoader = document.getElementById("pvPhotoLoader");
 pvPhotoLoader.onload = onPVload;
 changeImg(0);
}

function pausePV(e)
{
 if (pvPlay) { pvPlay = false; pvPhoto.title = "click to play"; }
 else { pvPlay = true; pvPhoto.title = "click to pause"; if (pvTimer && pvImgLoaded) displayPVImg(); }
}