var iPath;
var iExt   = 'gif';
var suffix = new Array('off', 'on');

function preLoad(){
	if(document.images){
		var argLen = arguments.length;
		for(var i = 0; i < argLen; i++){
			var arg = arguments[i];
			var sufLen = suffix.length;
			for(j = 0; j < sufLen; j++){
				var suf = suffix[j]
				self[arg + '-' + suf] = new Image();
				self[arg + '-' + suf].src = iPath + arg + '-' + suf + '.' + iExt;
			}
		}
	}
}

function rollOver(iName, iState){
	if(document.images && self[iName + '-' + iState]){
		document.images[iName].src = self[iName + '-' + iState].src;
	}
	return true;
}

function preloadTopNav(rootURL){ // preloads top navigation images
	iPath = rootURL + '/images/nav/';
	preLoad('but_play_now','but_rules','but_chat','but_winners','but_leaders','but_help');
}