switch问题

这段代码哪里出错？有红线，编不下去了。求教。
  private void Swap(int vNum,int blank)
        {
            Point temp;
         
            switch(vNum)
            {
            case1:
               temp = lbl1.Location;
               lbl1.Location = lblBlank.Location;
               lblBlank.Location = temp;
                break;
            case 2:
            temp =lbl2.Location ;
            lbl2.Location =lblBlank .Location ;
            lblBlank .Location =temp;
            break;

            }
        }