[iKarim]

PHP код:

// above in defines
#define     ClearChat(%0)     for (new i = 0; i < 40; i++) SendClientMessage(%0, -1, " ")

public OnPlayerConnect(playerid)
{
    ClearChat(playerid);
    new string[SOS];
    GetPlayerName(playerid, pInfo[playerid][Nick], 20);
    GetPlayerIp(playerid, pInfo[playerid][Ip], 16);
    format(string, SOS, "*** %s has joined the server.", pInfo[playerid][Nick]);
    SendClientMessageToAll(ORANGE, string);
    if(fexist(UserPath(playerid)))
    {
        INI_ParseFile(UserPath(playerid), "LoadUser_%s", .bExtra = true, .extra = playerid);
        ShowPlayerDialog(playerid, DIALOG_LOGIN, DIALOG_STYLE_INPUT,"{FFFFFF}Login","{FFFFFF}Type your password to login.","Login","Quit");
    }
    else
    {
        ShowPlayerDialog(playerid, DIALOG_REGISTER, DIALOG_STYLE_INPUT,"{FFFFFF}Registering...","{FFFFFF}Type your password  to register","Register","Quit");
    }
    return 1;
} 


This should work, and you don't have to type 'sendclientmessage' 20times to clear the chat, just use a macro.