try {
  document.execCommand('BackgroundImageCache', false, true);
} catch(e) {}
function pop (imgtag, width, height, alt){
	width += 32;
	height += 40;
	if (alt != ''){
		height += 16;
	}
	var features = 'location=0,statusbar=0,scrollbars=1,menubar=0,width='+width+',height='+height+',resizable=1';
    var target   = '_blank';
    var url = 'showimg.php?img='+imgtag+'&alt='+alt;
    var theWindow = window.open(url, target, features);
    theWindow.focus();
    return false;
}