菜鸟请教高手个问题！！紧急！sliverligt 获取webservice返回值问题

Question

silverlight页面的代码  private void enter_Click(object sender, RoutedEventArgs e)  {  Service1SoapClient client = new Service1SoapClient();  string name = this.Name.Text;  string pwd = this.Pwd.Password;  int i=client.select_adminAsync(name,pwd);  }webservice页面的代码 [WebMethod]  public int select_admin(string name,string pwd)  {  string sql = "select * from admin where Name='" + name + "'and Password='" + pwd + "'";  DataSet ds = DbHelpSQL.ExecuteGetData(sql);  if (ds.Tables[0].Rows.Count > 0)  {  return 1;  }  else  {  return 0;  }为什么调用方法的时候会说无法将void隐士转换为int 我方法的返回值明明是int 该怎么样才可以调用或者获取返回值