多线程中检测某个.asmx链接是否有效,该怎么解决

try {   System.Net.WebRequest   myRequest   =   System.Net.WebRequest.Create( "http://192.168.0.6/rootserver/DirService.asmx ");   System.Net.WebResponse     myResponse   =   myRequest.GetResponse(); return   "ok "; } catch(Exception   ex) { return   ex.Message.ToString(); } 

//引入命名空间MSXML2using MSXML2;public bool getWSStatus()        {            string url = "http://192.168.105.10/hotelwebsrv/hotelwebsrv.asmx";            XMLHTTP http = new XMLHTTP();            try            {                http.open("GET", url, false, null, null);                http.send(null);                int iStatus = http.status;                //如果取得的网页状态不正确,   就是不存在或没权访问                   if (iStatus == 200)                    return true;                else                    return false;            }            catch            {                return false;            }        }