// home.js

function showLayer(id) {
	if (!initialized) return;
	hideAllLayers();
	
	var obj = (isDOM)?document.getElementById(id):(isIE4)?document.all[id]:(isNS4)?document.layers[id]:null;
	if (isNS4) obj.style = obj;
	
	obj.style.visibility = (isNS4)?"show":"visible";
}

function hideLayer(id) {
	if (!initialized) return;
	
	var obj = (isDOM)?document.getElementById(id):(isIE4)?document.all[id]:(isNS4)?document.layers[id]:null;
	if (isNS4) obj.style = obj;
	
	obj.style.visibility = (isNS4)?"hide":"hidden";
}

function hideAllLayers() {
	// Resources for:
	hideLayer("architects");
	hideLayer("firms");
	hideLayer("homeowners");
	hideLayer("industry");
	hideLayer("interns");
	hideLayer("media");
	hideLayer("vendors");
	// Services:
	hideLayer("advertise");
	hideLayer("buy");
	hideLayer("findcommittee");
	hideLayer("findconsultant");
	hideLayer("findjob");
	hideLayer("findarchitect");
	hideLayer("join");
	hideLayer("search");
}

function genRandNum(lower,upper) {
	return Math.floor(Math.random()*upper) + lower;
}

var numPhotos = 4;
var photoIncrementer=2;
var arrUnique = new Array();

function changePhoto() {
	
	if (photoIncrementer<=(numPhotos)) {
		swapImage("bgphoto",arBgPhoto[photoIncrementer-1].src);
		swapAlt("bgphoto",arBgPhotoAlts[photoIncrementer-1]);
		swapLink("bsa_custom_bgphoto_link",arBgPhotoLinks[photoIncrementer-1]);
		photoIncrementer++;
	} else {
		photoIncrementer=2;
		swapImage("bgphoto",arBgPhoto[0].src);
		swapAlt("bgphoto",arBgPhotoAlts[0]);
		swapLink("bsa_custom_bgphoto_link",arBgPhotoLinks[0]);
	}

}

function checkNavZone(arg) {
	if (!initialized) return;
	e = (arg)?arg:event;
	mX = (e.pageX)?e.pageX:e.clientX;
	mY = (e.pageY)?e.pageY:e.clientY;
	//window.status = "x="+mX+" y="+mY;
	var navL = 175;
	var navR = 527;
	var navT = 110;
	var navB = 232;
	if ((mX<navL)||(mX>navR)||(mY<navT)||(mY>navB)) {
		hideAllLayers();
	}
}

function init() {
	arBgPhoto = preloadImages(
	"bsa_custom_images/home/bgphoto/01.jpg",
	"bsa_custom_images/home/bgphoto/02.jpg",
	"bsa_custom_images/home/bgphoto/03.jpg",
	"bsa_custom_images/home/bgphoto/04.jpg");
	
	arBgPhotoLinks = preloadLinks(
	"http://www.architects.org/clickthru.cfm?WT.mc_id=100002&durl=membership%2Findex.cfm%3Fdoc_id%3D12",
	"http://www.architects.org/clickthru.cfm?WT.mc_id=100003&durl=http%3A%2F%2Fwww.buildboston.com",
	"http://www.architects.org/clickthru.cfm?WT.mc_id=100004&durl=http%3A%2F%2Fwww.rotchscholarship.org",
	"http://www.architects.org/clickthru.cfm?WT.mc_id=100005&durl=classifieds%2Flist_classifieds.cfm");
	
	arBgPhotoAlts = preloadAlts(
	"Renew your membership",
	"Build Boston is November 18-20",
	"Rotch Traveling Scholarship, study architecture, travel the world",
	"BSA Classifieds - search new job listings");
	
	var si = setInterval("changePhoto()",6000);
	initialized = true;
}

var arBgPhoto = new Array();
var arBgPhotoLinks = new Array();
var arBgPhotoAlts = new Array();
var initialized = false;

window.onload=init;