int              Minute5;              //global to hold 5 minute number

//+------------------------------------------------------------------+
//| expert start function                                            |
//+------------------------------------------------------------------+
void init()
{
   Minute5 = TimeMinute(TimeCurrent()) / 5;
}
//+------------------------------------------------------------------+   
int start()
{
      if (ManageOpenOrders() > 0)
      {
         return(0);
      }
      else
      {
         if ( (TimeMinute(TimeCurrent()) / 5) != Minute5 )
         {
            Minute5 = TimeMinute(TimeCurrent()) / 5;     //reload variable at first tick of every candle
            // check trade criterion ...