/*
	dom checker
*/
dom = (document.getElementById)? true : false;
ie4 = (document.all)? true : false;
ns6= (dom && !ie4)? true : false;
ns4 = (document.layers)? true:false;

function toggleDisplay(obj1Name, obj2Name) {
	/*
		function to show and hide the signin and signout ids 
		made for the GCCI login bar
	*/
	
	// get the object
	objSignin = getObject(obj1Name);
	objSignout = getObject(obj2Name);
	
	if (objSignout.style.display == 'none') {
		// show the singout
		objSignout.style.display = 'block';
		objSignin.style.display = 'none';
	} else {
		// show the singin
		objSignout.style.display = 'none';
		objSignin.style.display = 'block';
	}
}

function getObject(oID) {
	/*
		function that returns the element based on the browser
		capitalities - ns4 will return null if the obj doesn't exist
	*/
	if (dom) {
		obj = document.getElementById(oID);
	} else if (ie4) {
		obj = document.all(oID);
	} else if (ns4) {
		obj = document.layers(oID);
		if (!obj)
			return null;
	}
	return obj;
}

function preloadImage(imgObj,imgSrc) {
	/*
		function to preload images
	*/
	if (document.images) {
		eval(imgObj+' = new Image()');
		eval(imgObj+'.src = "'+imgSrc+'"');
	}
}

function changeImage(imgName,imgObj,layer) {
	/*
		function to do rollovers of images
	*/
	if (document.images) {
		if (document.layers) {
			if (layer!=null){
				eval('document.layers.'+layer+'.document.images["'+imgName+'"].src = '+imgObj+'.src');
			} else {
				document.images[imgName].src = eval(imgObj+".src");
			}
		} else {
			document.images[imgName].src = eval(imgObj+".src");
		}
	}
}