Additional information:

main:
serout2 tx,baud,["AT^SMGR=1",13] ' I have tried it with AT+CMGR=1
Serin2 rx,baud,5000,main,[WAIT("REC UNREAD")] ' I have tried this string with REC READ, STO UNSENT, STO SENT - Nothing works!
portc=255
end