SetStopLoss

extern int StopLoss=50;

int start()
  {
   for(int cnt=OrdersTotal();cnt>=0;cnt--)
     { 
       if(OrderSelect(cnt, SELECT_BY_POS, MODE_TRADES)==true) 
          {
              if(OrderType()==OP_BUY && OrderStopLoss()==0)   
                 {
                     OrderModify(OrderTicket(),0,OrderOpenPrice()-StopLoss*Point,OrderTakeProfit(),0,CLR_NONE);
                 }
              if(OrderType()==OP_SELL && OrderStopLoss()==0)   
                 {
                     OrderModify(OrderTicket(),0,OrderOpenPrice()+StopLoss*Point,OrderTakeProfit(),0,CLR_NONE);
                 }
          }                       
     }
   }