/*
*   type:第几层调用,根目录为:1,再下一层:2,以此类推
*   methodName:webservices的方法名称
*   callback:回调函数(处理函数)
*   pars:参数集合,可以这样使用,调用时 '{参数名:参数值}' 如:WebService('gm.asmx/GetAllPZ',PZCall,'{type:"'+type+'"}'); 
*/
function AjaxGet(type,methodName,callback,pars)
{
    var url="gm.asmx/";
    var index="";
    switch(type){
        case 1:
            index="";
        break;
        case 2:
            index="../";
        break;
        case 3:
            index="../../";
        break;
    }
    url=index+url+methodName;
    $.ajax(
    { 
        data:pars, 
        url: url, 
        type: "POST", 
        contentType: "application/json;utf-8", 
        dataType:'json', 
        cache: false, 
        success: function(json)
        { 
            callback(json.d);
        }, 
        error:function(xml,status)
        { 
            if(status=='error')
            { 
                try
                { 
                    //var json = eval('(' + xml.responseText + ')'); 
                    //alert(json.Message+'\n'+json.StackTrace); 
                    alert("请求失败,请确保网络连接正常或无非法提交");
                    //history.go(0);
                }catch(e){} 
            }else{ 
                alert(status); 
            } 
        }, 
        beforeSend:function(xml)
        { 
            if(!pars) xml.setRequestHeader("Content-Type", "application/json;utf-8") 
        } 
    }); 
}