var topnavTimerID;
var cssclass_off = "dropdown off";
var cssclass_over = "dropdown";
var disappeardelay=150;

function topnav_preload() {
	var preloaded = new Array();
	for (i=0;i<arguments.length;i++) {
		preloaded[i] = new Image();
		// preloaded[i].src = args[i];
        preloaded[i].src = '/img/nav_' + arguments[i] + '_over.gif';
	}
}

    
function swapMenu(name, mouse_is_on) {
	if (mouse_is_on) {
		clearTimeout(topnavTimerID);
		turnOff(name);
		changeClass(name, cssclass_over);
	} else {
		clearTimeout(topnavTimerID);
		topnavTimerID = setTimeout('turnOff("")', disappeardelay);
	}
}

function turnOff(name) {
	for (i=0; i<menudiv.length; i++) {
		if (name.indexOf(menudiv[i])==-1) {
			changeClass(menudiv[i], cssclass_off);
		} 
	}
}