var http_request = false;
function send_request(method,url,content,responseType,callback){
		http_request=false;
		if (window.XMLHttpRequest)
		{
			http_request=new XMLHttpRequest();
			if (http_request.overrideMimeType)
			{
				http_request.overrideMimeType("text/xml");
			}
		}
		else if (window.ActiveXObject)
		{
			try{
					http_request=new ActiveXObject("Msxml2.XMLHTTP");
			}catch(e){
				try{
					http_request=new ActiveXObject("Microsoft.XMLHTTP");
				}catch(e){}
			}
		}
		if (!http_request)
		{
			window.alert("不能创建XMLHttpRequest对象实例");
			return false;
		}
		if (responseType.toLowerCase()=="text")
		{
			http_request.onreadystatechange=callback;
		}
		else if (responseType.toLowerCase()=="xml")
		{
			http_request.onreadystatechange=callback;
		}
		else
		{
			window.alert("响应类别参数错误");
			return false;
		}
		if (method.toLowerCase()=="get")
		{
			http_request.open(method,url,true);
		}
		else if (method.toLowerCase()=="post")
		{
			http_request.open(method,url,true);
			http_request.setRequestHeader("content-type","application/x-www-form-urlencoded");
		}
		else 
		{
			window.alert("http请求类别参数错误");
			return false;
		}
		http_request.send(content);
}