Load a Workspace in gui

in my gui, i have to load variables from something.mat . but in that case, i have to load the workspace every time in callback function of each component., how to sort it out? changing the variables to global in the workspace an having it run ti the gui_openingfcn doesn't work and repetedly loading the workspace is just slowing down the program functioning. what to do?

[Walter Roberson]

http://matlab.wikia.com/wiki/FAQ#How_can_I_share_data_between_callback_functions_in_my_GUI.3F