Creating a terminal similar to Matlab terminal in a GUI

Hi,

I want to create a terminal window much like the Matlab command window which will periodically display messages and I am able to scroll through them freely.

Right now I've kind of accomplished that by using listbox.

function main()

this.gui_h = guidata(messages);

    for i = 1:500
        pause(0.5);
        outputString = sprintf('I am %d years old', i);

        oldmsgs = cellstr(get(this.gui_h.window_disp,'String'));
        set(this.gui_h.window_disp, 'String',[oldmsgs; {outputString}] );

    end
end

One slight problem is that since the string always updates it stuffs up the scrollbar and is not very userfriendly. I have trouble freely scrolling through past messages as it constantly updates to the latest messages.

Any fix? I've attached my gui figure file...