function isIE5() { return (navigator.userAgent.indexOf("MSIE 5") > -1); }
function isIE6() { return ((navigator.userAgent.indexOf("MSIE 6") > -1) && (navigator.userAgent.indexOf("Opera") == -1)); }
function isIE() { return (isIE5() || isIE6());}

function fixpng()
{
for (var i = 0; i < document.images.length; i++) {
var img = document.images[i];
imgSrc = img.src;
if (imgSrc.substr(imgSrc.length-3).toLowerCase() == "png") {
var w, h;
w = img.width, h = img.height;
img.src = "images/blank.gif";
img.width = w, img.height = h;
img.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src=\'" + imgSrc + "\', sizingMethod='scale');";
}
}
}
var isIE = isIE();
if ( isIE ) window.attachEvent("onload", fixpng);