function findObjById(objName) {
	var obj = null;

	if ( document.getElementById ) {
		obj = document.getElementById(objName);
	} else if ( !(obj = document[objName]) && document.all ) {
		obj = document.all[objName];
	}
	return obj;
}

// preload the images
if (document.images) {
	// preload the hover images
	document.hoverimages = new Array();
	document.hoverimages[1] = new Image();
	document.hoverimages[1].src = '/images/navbar-events-hover.gif';
	document.hoverimages[2] = new Image();
	document.hoverimages[2].src = '/images/navbar-programs-hover.gif';
	document.hoverimages[3] = new Image();
	document.hoverimages[3].src = '/images/navbar-news-hover.gif';
	document.hoverimages[4] = new Image();
	document.hoverimages[4].src = '/images/navbar-links-hover.gif';
	document.hoverimages[5] = new Image();
	document.hoverimages[5].src = '/images/navbar-contacts-hover.gif';
	document.hoverimages[6] = new Image();
	document.hoverimages[6].src = '/images/navbar-sitemap-hover.gif';

	// preload the original image names
	document.normalimages = new Array();
	document.normalimages[1] = new Image();
	document.normalimages[1].src = '/images/navbar-events.gif';
	document.normalimages[2] = new Image();
	document.normalimages[2].src = '/images/navbar-programs.gif';
	document.normalimages[3] = new Image();
	document.normalimages[3].src = '/images/navbar-news.gif';
	document.normalimages[4] = new Image();
	document.normalimages[4].src = '/images/navbar-links.gif';
	document.normalimages[5] = new Image();
	document.normalimages[5].src = '/images/navbar-contacts.gif';
	document.normalimages[6] = new Image();
	document.normalimages[6].src = '/images/navbar-sitemap.gif';
}

// load the "active" navbar image
if ( document.body || document.getElementsByTagName || document.all) {
	var bodyid;
	if ( document.body ) {
		bodyid = document.body.id;
	} else if ( document.getElementsByTagName ) {
		bodyid = document.getElementsByTagName("body")[0].id;
	} else {
		bodyid = document.all.tags("body")[0].id;
	}
	// SWITCH bodyid
	if ( bodyid ==
		'homepage' ) {
			document.normalimages[1].src = '/images/navbar-events-hover.gif';
			document.navEventsImage.src = document.normalimages[1].src;
			} else if ( bodyid ==
		'programs' || bodyid ==
		'directory' ) {
			document.normalimages[2].src = '/images/navbar-programs-hover.gif';
			document.navProgramsImage.src = document.normalimages[2].src;
			} else if ( bodyid ==
		'whatsnew' || bodyid ==
		'announcements' || bodyid ==
		'press' ) {
			document.normalimages[3].src = '/images/navbar-news-hover.gif';
			document.navNewsImage.src = document.normalimages[3].src;
			} else if ( bodyid ==
		'links' ) {
			document.normalimages[4].src = '/images/navbar-links-hover.gif';
			document.navLinksImage.src = document.normalimages[4].src;
			} else if ( bodyid ==
		'contacts' || bodyid ==
		'board' || bodyid ==
		'exhibitors' ) {
			document.normalimages[5].src = '/images/navbar-contacts-hover.gif';
			document.navContactsImage.src = document.normalimages[5].src;
			} else if ( bodyid ==
		'sitemap' ) {
			document.normalimages[6].src = '/images/navbar-sitemap-hover.gif';
			document.navSitemapImage.src = document.normalimages[6].src;
	}
}

// the image rollover methods
function swapImage(imageObj, hover, srcIndex) {
	if (!document.images) return;

	if ( hover == 'on' ) {
		imageObj.src = document.hoverimages[srcIndex].src;
	} else {
		imageObj.src = document.normalimages[srcIndex].src;
	}
		
}
function swapNavEvents() {
	swapImage(document.navEventsImage, 'on', 1);
}
function restoreNavEvents() {
	swapImage(document.navEventsImage, 'off', 1);
}
function swapNavPrograms() {
	swapImage(document.navProgramsImage, 'on', 2);
}
function restoreNavPrograms() {
	swapImage(document.navProgramsImage, 'off', 2);
}
function swapNavNews() {
	swapImage(document.navNewsImage, 'on', 3);
}
function restoreNavNews() {
	swapImage(document.navNewsImage, 'off', 3);
}
function swapNavLinks() {
	swapImage(document.navLinksImage, 'on', 4);
}
function restoreNavLinks() {
	swapImage(document.navLinksImage, 'off', 4);
}
function swapNavContacts() {
	swapImage(document.navContactsImage, 'on', 5);
}
function restoreNavContacts() {
	swapImage(document.navContactsImage, 'off', 5);
}
function swapNavSitemap() {
	swapImage(document.navSitemapImage, 'on', 6);
}
function restoreNavSitemap() {
	swapImage(document.navSitemapImage, 'off', 6);
}

// set the event handlers
var obj;
if ( obj = findObjById('navEventsLink') ) {
	obj.onmouseover = swapNavEvents;
	obj.onmouseout = restoreNavEvents;
	obj.onfocus = swapNavEvents;
	obj.onblur = restoreNavEvents;
}
if ( obj = findObjById('navProgramsLink') ) {
	obj.onmouseover = swapNavPrograms;
	obj.onmouseout = restoreNavPrograms;
	obj.onfocus = swapNavPrograms;
	obj.onblur = restoreNavPrograms;
}
if ( obj = findObjById('navNewsLink') ) {
	obj.onmouseover = swapNavNews;
	obj.onmouseout = restoreNavNews;
	obj.onfocus = swapNavNews;
	obj.onblur = restoreNavNews;
}
if ( obj = findObjById('navLinksLink') ) {
	obj.onmouseover = swapNavLinks;
	obj.onmouseout = restoreNavLinks;
	obj.onfocus = swapNavLinks;
	obj.onblur = restoreNavLinks;
}
if ( obj = findObjById('navContactsLink') ) {
	obj.onmouseover = swapNavContacts;
	obj.onmouseout = restoreNavContacts;
	obj.onfocus = swapNavContacts;
	obj.onblur = restoreNavContacts;
}
if ( obj = findObjById('navSitemapLink') ) {
	obj.onmouseover = swapNavSitemap;
	obj.onmouseout = restoreNavSitemap;
	obj.onfocus = swapNavSitemap;
	obj.onblur = restoreNavSitemap;
}