rtbme17 - if you have (for example) variables in your OpeningFcn that you want to reference later, then save them to the handles structure. For example,
function GUI_OpeningFcn(hObject, eventdata, handles, varargin)
% do some stuff
x = 42;
% save x to the handles structure
handles.x = x;
guidata(hObject, handles);
Note that the guidata(hObject, handles); is important as it will save the updated handles structure so that all other callbacks have access to this updated structure (and so can access x). Then in some callback you would do
function pushbutton1_Callback(hObject, eventdata, handles)
% use x
if isfield(handles, 'x')
y = handles.x * 2;
% etc.
end
In the above, we check to see if x is a fields within handles before trying to use it.
