browserName = navigator.appName;
browserVer = parseInt(navigator.appVersion);
if ((browserName == "Netscape" && browserVer >= 3) || (browserName == "Microsoft Internet Explorer" && browserVer >= 4) ) 
	hasImageObject = true;
else 
	hasImageObject = false;

if (hasImageObject) {
	home_on = new Image();
	home_off = new Image();
	home_on.src = "../images/homea.gif";
	home_off.src = "../images/homed.gif";
	reg_on = new Image();
	reg_off = new Image();
	reg_on.src = "../images/rega.gif";
	reg_off.src = "../images/regd.gif";
	query_on = new Image();
	query_off = new Image();
	query_on.src = "../images/querya.gif";
	query_off.src = "../images/queryd.gif";
	cont_on = new Image();
	cont_off = new Image();
	cont_on.src = "../images/conta.gif";
	cont_off.src = "../images/contd.gif";
}

function ImageOn(imgName) {
	if (hasImageObject) {
		document[imgName].src = eval(imgName + "_on.src");
	}
}

function ImageOff(imgName) {
	if (hasImageObject) {
		document[imgName].src = eval(imgName + "_off.src");
	}
}