var imgName = null;
var imgFile = null;
browserName = navigator.appName;
browserVer = parseInt(navigator.appVersion);
ns3up = (browserName == "Netscape" && browserVer >= 3);
ie4up = (browserName.indexOf("Microsoft") >= 0 && browserVer >= 4);

function doPic(imgName, imgFile) {
	if (!document.images)
	return
	if (ns3up || ie4up) {
	imgOn = ("" + imgFile);
	di = ("" + imgName);
	document.images[di].src = imgOn;
	
    }  
}