var xb ={
	evtHash: [],
	ieGetUniqueID: function(_elem) {
		if (_elem === window) { return 'theWindow'; }
		else if (_elem === document) { return 'theDocument'; }
		else { return _elem.uniqueID; }
	},
	addEvent: function(_elem, _evtName, _fn, _useCapture) {
		if (typeof _elem.addEventListener != 'undefined') {
			if (_evtName == 'mouseenter')
				{ _elem.addEventListener('mouseover', xb.mouseEnter(_fn), _useCapture); }
			else if (_evtName == 'mouseleave')
				{ _elem.addEventListener('mouseout', xb.mouseEnter(_fn), _useCapture); } 
			else
				{ _elem.addEventListener(_evtName, _fn, _useCapture); }
		}
		else if (typeof _elem.attachEvent != 'undefined') {
			var key = '{FNKEY::obj_' + xb.ieGetUniqueID(_elem) + '::evt_' + _evtName + '::fn_' + _fn + '}';
			var f = xb.evtHash[key];
			if (typeof f != 'undefined')
				{ return; }
			
			f = function() {
				_fn.call(_elem);
			};
			xb.evtHash[key] = f;
			_elem.attachEvent('on' + _evtName, f);
				// attach unload event to the window to clean up possibly IE memory leaks
			window.attachEvent('onunload', function() {
				_elem.detachEvent('on' + _evtName, f);
			});
			key = null;
			//f = null;   /* DON'T null this out, or we won't be able to detach it */
		}
		else
			{ _elem['on' + _evtName] = _fn; }
	},	
	removeEvent: function(_elem, _evtName, _fn, _useCapture) {
		if (typeof _elem.removeEventListener != 'undefined') { 
			_elem.removeEventListener(_evtName, _fn, _useCapture); }
		else if (typeof _elem.detachEvent != 'undefined') {
			var key = '{FNKEY::obj_' + xb.ieGetUniqueID(_elem) + '::evt' + _evtName + '::fn_' + _fn + '}';
			var f = xb.evtHash[key];
			if (typeof f != 'undefined') {
				_elem.detachEvent('on' + _evtName, f);
				delete xb.evtHash[key];
			}
			key = null;
			//f = null;   /* DON'T null this out, or we won't be able to detach it */
		}
	},
	mouseEnter: function(_pFn) {
		return function(_evt)
		{
			var relTarget = _evt.relatedTarget;				
			if (this == relTarget || xb.isAChildOf(this, relTarget))
				{ return; }
			_pFn.call(this, _evt);
		}
	},
	isAChildOf: function(_parent, _child) {
		if (_parent == _child) { return false };
		while (_child && _child != _parent)
			{ _child = _child.parentNode; }
		return _child == _parent;
	}	
};