C#1秒内判断是否已连上webservice，未连上则报错

　　　　      private bool isopen = false;//字段       
　　private void button1_Click(object sender, EventArgs e)
        {
            timer1.Enabled = true;
            timer1.Interval = 1000;//1秒内检查是否已连上网络
            WindowsFormsApplication1.ServiceReference1.SynWebSvrSoapClient s = new WindowsFormsApplication1.ServiceReference1.SynWebSvrSoapClient();
            isopen = s.OpenWeb();//该webservice方法为返回值为bool
        }

 

        private void timer1_Tick(object sender, EventArgs e)
        {
            timer1.Enabled = false;
            if (!isopen)
            {
                MessageBox.Show("未连上网络请检查设置");
               
            }
         
        }