[gamer931215]

You've forgotten to declare the color at SendClientMessage! its SendClientMessage(playerid,color,msg) and did you put the code under "OnPlayerCommandText" ?
like:

pawn Код:

public OnPlayerCommandText(playerid, cmdtext[])
{
    if (strcmp("/heal", cmdtext, true, 10) == 0)
    {
        SetPlayerHealth(playerid,100);
        SendClientMessage(playerid,0xFFFFFF,"You have been healed!");
        return 1;
    }
    return 0;
}