try
{ 
    document.execCommand("BackgroundImageCache",false,true);
}
catch(e){ }

onload = function()
{
    if(typeof selectedTab=='string') Element.appendClass(selectedTab, "selected");
    if(typeof window_onload == "function") window_onload();
} 

onunload = function()
{
    if(typeof window_onunload == "function") window_onunload();
}

showScreen = function()
{
    var o = $("imageScreen")
    Element.removeClass(o, "hidden");
    var h;
    try{ h=Math.max(document.getElementsByTagName('html')[0].clientHeight, document.body.clientHeight)} 
    catch(e){h=document.body.clientHeight}
    if(parseFloat(o.style.height)!= h) o.style.height = h + "px";
}
hideScreen = function()
{
    Element.appendClass("imageScreen", "hidden");    
}