function $(id)
{
	return document.getElementById(id);
}
function Ajax()
{
	var xhrObj=null; 
	if(window.XMLHttpRequest) 
	{ 
		xhrObj=new XMLHttpRequest(); 
	} 
	else if(window.ActiveXObject) 
	{ 
		try
		{ 
			xhrObj=new ActiveXObject("Microsoft.XMLHTTP"); 
		} 
		catch(e1) 
		{ 
			try
			{ 
				xhrObj=new ActiveXObject("MSXML2.XMLHTTP"); 
			} 
			catch(e2)
			{ 
				try
				{ 
					xhrObj=new ActiveXObject("MSXML3.XMLHTTP"); 
				} 
				catch(e3)
				{ 
					alert("创建Ajax失败："+e3) 
				} 
			} 
		} 
	} 
	else 
	{ 
		alert("未能识别的浏览器"); 
	} 
	return xhrObj; 
}