Debug in Matlab GUIDE

1. add a button callback
with callback fcn. "keyboard".
one word!!!
2. get gui handle through guidata fcn.
e.g.
handleGUI = findobj(0, 'Tag','This is the GUI that I want to find')
handles = guidata(handleGUI);
%%% if handle visibility is set to 'off' or 'callback', it's better to use findall instead of findobj...

in reference to:

"handleGUI = findobj(0, 'Tag','This is the GUI that I want to find') and again: handles = guidata(handleGUI);"
- Adding a debug button to a MATLAB GUI. | Doug's MATLAB Video Tutorials (view on Google Sidewiki)