duck

    string consoleString = "";

    void OnGUI () {
        if (showConsole)
        {
            // Make a multiline text area that modifies stringToEdit.
            consoleString = GUI.TextArea(new Rect(10, 10, 300, 32), consoleString );
            if (GUI.Button(new Rect(10, 44, 50, 20), "go"))
            {
                ParseConsoleCommand(consoleString);
        consoleString = "";
            }
        }
    }