[Konstantinos]

Your braces are set bad in OnDialogResponse. Goto http://codegenerators.pl/indent to indent your code, and see yourself that the braces do not match each other (opened with closed) and you don't close the last brace at the end of OnDialogReponse

pawn Код:

public OnDialogResponse(playerid, dialogid, response, listitem, inputtext[])
{
    // code
    return 0;
} // < you forgot it.

Otherwise, if you cannot fix it yourself, then you have to post the OnDialogReponse so we'll be able to fix it for you.