[Pyrokid]

Untested but it should work:

pawn Код:

public OnPlayerDeath(playerid, killerid, reason)
{
    if(killerid == INVALID_PLAYER_ID)
    {
        //No message will show if the player commited suicide
    } else {
        new killername[16], playername[16], string[128];
        GetPlayerName(playerid,playername,MAX_PLAYER_NAME);
        GetPlayerName(killerid,killername,MAX_PLAYER_NAME);
        format(string,sizeof(string),"%s killed %s with a %s!",killername,playername,GetPlayerWeapon(killerid));
        SendClientMessageToAll(COLOR,string);
    }
    return 1;
}

Edit: Edited it a bit.