HI all,
I don't unerstand why the following command inserted into a custom block mql4:

OrderSend(Symbol(), OP_SELL, lots, Bid, 0, sl, tp, "Sell Order" ,group , 0, Red) ;

works correctly, while the following (buy) it doesn't work:

OrderSend(Symbol(), OP_BUY, lots, Ask, 0, sl, tp, "Buy Order", group, 0, Blue);

Thanks for everyone will answer.