[jlalt]

ShowPlayerDialog contains 7 arguments / parameters.
https://sampwiki.blast.hk/wiki/ShowPlayerDialog
(playerid, dialogid, style, caption[], info[], button1[], button2[])

and seems like you only wanna show "OK" button to do that keep the other button field empty, "".

Код:

 } else return ShowPlayerDialog(playerid, 1, DIALOG_STYLE_MSGBOX, "ERROR", "You need to be cgf Member to use this command", "OK", "");