var isIE4 = document.all ? 1 : 0;
var isW3C = document.getElementById ? 1 : 0;
var isIE6 = document.documentElement  && document.documentElement.clientHeight ? 1 : 0;  <!-- for explorer on PC window height -->
var imgID = new Array('home','program','proposal','history','specs','links','contact','whc');
var navImgOn = new Array();
var navImgOff = new Array();

function cacheImages(){
	for(i=0;i<imgID.length;i++){
		var nam = imgID[i];
		navImgOn[nam] = new Image;
		navImgOn[nam].src = "images/global/nav_"+nam+"_over.gif";
		navImgOff[nam] = new Image;
		navImgOff[nam].src = "images/global/nav_"+nam+"_off.gif";
	}
}

function rollOn(nam){
	document.images[nam].src=navImgOn[nam].src;
	return true;
}

function rollOff(nam){
	document.images[nam].src=navImgOff[nam].src;
	return true;
}


function makeIFrame(pagename){
	if (isIE6) {
		setHeight = document.documentElement.clientHeight - 176;
	} else if (isIE4) {
		setHeight = document.body.clientHeight - 176;
	} else {
		setHeight = window.innerHeight - 176;
	}
	document.write("<IFRAME id='"+pagename+"_frame' name='"+pagename+"_frame' style='position:absolute; height:"+setHeight+"px; left:170px; top:145px; z-index:6;' src='"+pagename+".html' scrolling='auto' width='505px' frameborder='0'></IFRAME>");
}