/**
 *
 */
function XHR(callback,pagetype){
	//ajax object Create------begain
	var request = false;
	try {
	  request = new XMLHttpRequest();
	} catch (trymicrosoft) {
	  try {
  	  request = new ActiveXObject("Msxml2.XMLHTTP");
	  } catch (othermicrosoft) {
	    try {
	      request = new ActiveXObject("Microsoft.XMLHTTP");
	    } catch (failed) {
	      request = false;
	    }
	  }
	}
	if (!request){
  	alert("Error initializing XMLHttpRequest!");
	}
	//ajax object Create------end
	this.geturl=function(url){
		request.open("GET", url , true);
		request.send(null);
	};
	this.posturl=function(url,args){
		request.open('post', url, true);
		request.setRequestHeader("Method", "POST " + url + " HTTP/1.1");
		request.setRequestHeader("Charset","GB2312");
		request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
		var arg_g_arr = args.split("&");
		for(key in arg_g_arr)
		{
			value_arr = arg_g_arr[key].split("=");
			value_arr[1] = encodeURI(value_arr[1]);
			arg_g_arr[key] = value_arr.join("=");
		}
		args = arg_g_arr.join("&");
		request.send(args);
	};
	request.onreadystatechange = function(){
		//0: Uninitialized	1: Loading	2: Loaded	3: Interactive	4: Finished
		if(request.readyState == 4){
			if (request.status == 200){
				if (typeof(callback)=="function"){
					if(pagetype=="xml"){
						callback(request.responseXML);
					}else{
						callback(request.responseText);
					}
				}
			}else{
    	  alert("Error: status code is " + request.status);
			}
		}
	}
}