aurc89 - in your push button callback, use the handles structure to refer back to your popup menu object named popupmenu1. For example,
function pushbutton1_Callback(hObject,eventdata,handles)
str = get(handles.popupmenu1, 'String');
val = get(handles.popupmenu1,'Value');
% etc.
Note that you may not need to get the string values back and can just use the integer val instead. (Also, in your popup menu callback, there is no need for the guidata(hObject,handles) because you haven't updated the handles structure..unless you haven't shown all of your code.) Try the above and see what happens!
