[Threshold]

pawn Код:

for(new i = 0; i < 100; i++) SendClientMessage(playerid, -1, " ");

The first guy had it right... there is total of 100 lines saved in a player's chat log on-screen at any time. So 200 would be useless and a waste of data. 29 wouldn't clear the entire chat. Using SendClientMessageToAll would clear everyone's chat, which I'm pretty sure he doesn't want.

pawn Код:

public OnPlayerConnect(playerid)
{
    for(new i = 0; i < 100; i++) SendClientMessage(playerid, -1, " ");
    return 1;
}

Simple...