if (document.images){
	var main = new Image();
		main.src="img/nav/main.gif";
	var exover = new Image();
		exover.src="img/nav/exover.gif";
	var conspot = new Image();
		conspot.src="img/nav/conspot.gif";
	var checklst = new Image();
		checklst.src="img/nav/checklst.gif";
	var relprog = new Image();
		relprog.src="img/nav/relprog.gif";
	var vinfo = new Image();
		vinfo.src="img/nav/vinfo.gif";
	
	var main_on = new Image();
		main_on.src="img/nav/main_on.gif";
	var exover_on = new Image();
		exover_on.src="img/nav/exover_on.gif";
	var conspot_on = new Image();
		conspot_on.src="img/nav/conspot_on.gif";	
	var checklst_on = new Image();
		checklst_on.src="img/nav/checklst_on.gif";
	var relprog_on = new Image();
		relprog_on.src="img/nav/relprog_on.gif";
	var vinfo_on = new Image();
		vinfo_on.src="img/nav/vinfo_on.gif";
}

function btnChange(name,onOff){
	// onOff is has a Boolean value.  True for a mouseover.  False for a mouseout.
	if (document.images){
		var imgFile = (onOff) ? eval(name+"_on.src") : eval(name+".src");
		window.document.images[name].src=imgFile;
	}
}

var popupWin;
// wit & hite will determine where the window opens on the screen
function openWin(windowURL,windowName,wit,hite,scroll) { 
	var winH = (screen.height - hite) / 2;
	var winW = (screen.width - wit) / 2;
	popupWin = window.open( windowURL, windowName, "menubar=no,status=no,toolbar=no,location=no,scrollbars="+scroll+",screenx=1,screeny=1,width=" + wit + ",height=" + hite + ",top="+winH+",left="+winW);
	popupWin.focus();
}