[JaTochNietDan]

Unknown command does not mean the command is broken, it means that you do not return a value in the command, which means it goes to the end of the OnPlayerCommandText function and hits your return 0, which tells the SA-MP client to send that default Unknown Command message. To fix this you should at a return 1; at the very end of the command. Also like I said, you need to move the ShowPlayerDialog function out of the loop. My posts have to be read in full to understand them, and if you don't understand, please say so, otherwise the help I'm providing is useless!