browser = (((navigator.appName == "Netscape") && (parseInt(navigator.appVersion) >= 3 )) || ((navigator.appName == "Microsoft Internet Explorer") && (parseInt(navigator.appVersion) >= 3 )))

function imgover(imgname) {
	if(browser) {
  	document[imgname].src = eval(imgname+"_over.src");
    return true;
  }
}
function imgnorm(imgname) {
	if(browser) {
	  document[imgname].src = eval(imgname+"_norm.src");
    return true;
  }
}