[iSkate]

For fixing the 1st error:

pawn Код:

public OnPlayerCommandText(playerid, cmdtext[])
{
        dcmd(help, 4, cmdtext);
    return 0;
}

For fixing the 2nd error and the warning:

pawn Код:

dcmd_help(playerid, params[])
{
    #pragma unused params
    new string[512];
    strcat(string, "Mode informations\n");