function pngAlpha(obj)
{
	if (navigator.appVersion.indexOf("MSIE 5") != -1 || navigator.appVersion.indexOf("MSIE 6") != -1)
	{
		var source = obj.src;
		if (obj && source.toLowerCase().indexOf(".png") != -1)
		{
			var ancho = obj.width;
			var alto = obj.height;
			obj.style.filter = "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='" + source + "')";
			obj.src = /.*\//.exec(source) + "transparent.gif";
			obj.width = ancho;
			obj.height = alto;
		}
	}
}