function addEvent(element, type, handler) {
    // assign each event handler a unique ID
    if (!handler.$$guid) handler.$$guid = addEvent.guid++;
    // create a hash table of event types for the element
    if (!element.events) element.events = {};
    // create a hash table of event handlers for each element/event pair
    var handlers = element.events[type];
    if (!handlers) {
        handlers = element.events[type] = {};
        // store the existing event handler (if there is one)
        if (element["on" + type]) {
            handlers[0] = element["on" + type];
        }
    }
    // store the event handler in the hash table
    handlers[handler.$$guid] = handler;
    // assign a global event handler to do all the work
    element["on" + type] = handleEvent;
};
// a counter used to create unique IDs
addEvent.guid = 1;
function removeEvent(element, type, handler) {
    // delete the event handler from the hash table
    if (element.events && element.events[type]) {
        delete element.events[type][handler.$$guid];
    }
};
function handleEvent(event) {
    // grab the event object (IE uses a global event object)
    event = event || window.event;
    // get a reference to the hash table of event handlers
    var handlers = this.events[event.type];
    // execute each event handler
    for (var i in handlers) {
        this.$$handleEvent = handlers[i];
        this.$$handleEvent(event);
    }
};
function $(el)
{
    return document.getElementById(el);
}
function hasClass(ele,cls) {
	return ele.className.match(new RegExp('(\\s|^)'+cls+'(\\s|$)'));
}
function addClass(ele,cls) {
	if (!this.hasClass(ele,cls)) ele.className += " "+cls;
}
function removeClass(ele,cls) {
	if (hasClass(ele,cls)) {
		var reg = new RegExp('(\\s|^)'+cls+'(\\s|$)');
		ele.className=ele.className.replace(reg,' ');
	}
}
function removeElementsChildren(ele)
{
    if (ele != null)
    {
        while(ele.childNodes[0] != null)
            ele.removeChild(ele.childNodes[0]);
    }
}
function convertToSmallQueryStringDate(year, month, day)
{
    month+=1;    
    if (month < 10)
        month = "0"+month+"";        
    if (day < 10)
        day = "0"+day+"";
    return year + ""+month+""+day;
}
// test if object is an array
function isArray(obj) {
    return (obj.constructor == Array);
}
function toggle(obj) {
	var el = $(obj);
	el.style.display = (el.style.display != 'none' ? 'none' : '' );
}
var xmlHttp;
function GetXmlHttpObject() {
    var xmlHttp = null;
    try {
        // Firefox, Opera 8.0+, Safari
        xmlHttp = new XMLHttpRequest();
    }
    catch (e) {
        // Internet Explorer
        try {
            xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
        }
        catch (e) {
            xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
    }
    return xmlHttp;
}