// JavaScript Document

function getXmlHttpRequest() {

	var xmlHttpObj;
	if (window.XMLHttpRequest)
	{
	xmlHttpObj = new XMLHttpRequest();	
	} else {
		try
		{
			xmlHttpObj = new ActiveXObject("Msxml2.XMLHTTP");
		}
		catch (e)
		{
			try
			{
				xmlHttpObj = new ActiveXObject("Microsoft.XMLHTTP");
			}
			catch (e)
			{
				xmlHttpObj = false;
			}
		}
	}
	
	return xmlHttpObj;

}//function getXmlHttpRequest

//screen out older IE versions
function screenIE() {
	if (navigator.appName == 'Microsoft Internet Explorer') {
		msie=navigator.appVersion.split("MSIE")
		version=parseFloat(msie[1]);
		if (version >= 6) return false;
	} else return false;
	return true;
}//function screenIE


//page 101 of adding Ajax book
function manageEvent(eventObj, event, eventHandler) {
	if (eventObj.addEventListener) {
		eventObj.addEventListener(event, eventHandler, false);
	}else if (eventObj.attachEvent) {
		event = "on" + event;
		eventObj.detachEvent(event, eventHandler);
	}// else if
}//function

function stopManagingEvent(eventObj, event, eventHandler) {
	if (eventObj.removeEventListener) {
		eventObj.removeEventListener(event, eventHandler, false);
	} else if (eventObj.detachEvent) {
		event = "on" + event;
		eventObj.detachEvent(event, eventHandler);
	} //else
}//function

function cancelEvent(event) {
	if (event.preventDefault){
		event.preventDefault();
		event.stopPropagation();
	} else {
		event.returnValue = false;
		event.cancelBubble = true;
	}//else
}//function

function setOpacity(obj,val)
{
	obj.style.opacity = val;
	obj.style.MozOpacity = val;
	obj.style.KhtmlOpacity = val;
	val*=100;
	obj.style.filter = "alpha(opacity="+val+")";
}