[Tanush123]

on top

pawn Код:

new talkascodename[MAX_PLAYERS],codename[20],ifcodename[MAX_PLAYERS],str[128];

on player text

pawn Код:

public OnPlayerText(playerid, text[])
{
    if(ifcodename[playerid] == 1)
    {
         return 0;
         format(str,sizeof(str),"%s: %s",talkascodename,text);
         SendClientMessageToAll(-1,str);
    }
    return 1;
}

command

pawn Код:

CMD:codename(playerid,params[])
{
   if(sscanf(params,"s",codename)) return SendClientMessage(playerid,grey,"USAGE: /codename [name]");
   if(ifcodename[playerid] == 0)
   {
       ifcodename[playerid] = 1;
       talkascodename[playerid] = codename;
   }
   else if(ifcodename[playerid] == 1)
   {
        ifcodename[playerid] = 0;
   }
   return 1;
}

i might failed but still, just try it.