I use MATLAB 7.1. If I open an existing GUI project built in 6.5 MATLAB with GUIDE tool, .fig is loaded correctly but .m is not loaded (it has the same name of .fig), then when I run the GUI and click on buttons I got function not found errors: ??? Undefined command/function 'fsv'. ??? Error while evaluating uicontrol Callback. How can I reassociate .m with his .fig?