CMD:id(playerid, params[]) { // Command initializer for zcmd
    new
        _playerID; // Create a variable for sscanf to process
        
    if(sscanf(params, "u", _playerID)) { // Using sscanf to parse the result.
        return SendClientMessage(playerid, SOME_COLOR, "Syntax: /id [playerid]"); // Send them a message showing the usage of the command (they didn't use the proper command usage). Define SOME_COLOR or replace it
    }
    else { // They added the proper usage. Continue with the code.
        if(_playerID == INVALID_PLAYER_ID) return SendClientMessage(playerid, SOME_COLOR, "That person is not connected."); // Send them a message, the ID/name is not connected
        // If it continues past the code above (^), then the player is connected.
        new
            _playerMsgFormatSz[50], // Create the variable to format the message we'll send.
            _playerNameSz[MAX_PLAYER_NAME]; // Create the variable to retrieve the players name.
            
        GetPlayerName(_playerID, _playerNameSz, MAX_PLAYER_NAME); // Get the players name.
            
        format(_playerMsgFormatSz, sizeof(_playerMsgFormatSz), "%s (%d) is connected.", _playerNameSz, _playerID); // Format the message.
        return SendClientMessage(playerid, SOME_COLOR, _playerMsgFormatSz); // Send the message
    }
}