var http_request=false;
	var reobj;
  function send_request(url){//初始化，指定处理函数，发送请求的函数
    http_request=false;
	//开始初始化XMLHttpRequest对象
	if(window.XMLHttpRequest){//Mozilla浏览器
	 http_request=new XMLHttpRequest();
	 if(http_request.overrideMimeType){//设置MIME类别
	   http_request.overrideMimeType("text/xml;charset=gb2312");
	 }
	}
	else if(window.ActiveXObject){//IE浏览器
	 try{
	  http_request=new ActiveXObject("Msxml2.XMLHttp");
	 }catch(e){
	  try{
	  http_request=new ActiveXobject("Microsoft.XMLHttp");
	  }catch(e){}
	 }
    }
	if(!http_request){//异常，创建对象实例失败
	 window.alert("创建XMLHttp对象失败！");
	 return false;
	}
	http_request.onreadystatechange=processrequest;
	//确定发送请求方式，URL，及是否同步执行下段代码
    http_request.open("GET",url,true);
	http_request.send(null);
  }
  //处理返回信息的函数
  function processrequest(){
   if(http_request.readyState==4){//判断对象状态
     if(http_request.status==200){//信息已成功返回，开始处理信息

	document.getElementById(reobj).innerHTML=http_request.responseText;
	

	 }
	 else{//页面不正常
	  alert("您所请求的页面不正常！");
	 }
   }
  }

function getCarList(objCar,cartype)
{
		 var cbd;
	  if(cartype=="1")
	  {
			var	cbd=$("sel_CarBrand").value;
			if(cbd=="")
			{alert('请选择品牌');return ;}
			else
			{ send_request("getCarsList.php?cbd="+cbd+"&type=1"+"&nocache="+new Date().getTime());
			reobj=objCar;
			}
	  }else
	  {
			var	cbd=$("sel_CarSeries").value;
			if(cbd=="")
			{alert('请选择系列');return ;
			}else
			{ send_request("getCarsList.php?cbd="+cbd+"&type=2"+"&nocache="+new Date().getTime());
				reobj=objCar;
			}
	   }
}

  function getclass(objCar,cartype){

	
	  var cbd;
	  if(cartype=="1")
	  {
			var	cbd=$("sel_CarBrand").value;
			if(cbd=="")
			{
			//alert('请选择品牌1');
			return ;
			}else
			{
			 send_request("getCar.php?cbd="+cbd+"&type=1"+"&nocache="+new Date().getTime());
						reobj=objCar;
			}
			
	  }else
	  {
			var	cbd=$("sel_CarSeries").value;
			if(cbd=="")
			{
			//alert('请选择系列1');
			return ;
			}else
			{
				 send_request("getCar.php?cbd="+cbd+"&type=2"+"&nocache="+new Date().getTime());
				 reobj=objCar;
			}
	   }
  }
  function getCar(objCar)
  {
	         var cbd;
			var cbd=$("sel_CarBrand").value;

			if(cbd=="")
			{
				 alert('请选择品牌');
			return false;
			}else
			{
			send_request("getCar.php?cbd="+cbd+"&type=3"+"&nocache="+new Date().getTime());
  	 		reobj=objCar;	
			}
	  }