how do i disable a button so that the client/server cannot click on it anymore? quick reply would be highly appreciated.. =)

button_state(PANEL*,var num,var state)

I'd use pan_setbutton.

pan_setbutton(bm_mainPan, 1, 1, 304, 208, bm_nullbuttonTGA, bm_nullbuttonTGA, bm_nullbuttonTGA, NULL, NULL, NULL, NULL);

It's not the nicest way of doing things, so if you have tons and tons of buttons, don't use it. But if there's only a few, this is a quick way.
Simply set all functions that the button calls to "NULL" and set all images of the button to the same button.