how to display serial com device data in edittext of gui

Hi experts,

            i want a GUI to be shown on the monitor always which has 1 simple edit text handle.
i have a device which sends a sentence once in a while to the dedicated com port of the PC. now i just want to display the text coming from the com port to the edit text handle of the GUI. but the process of receiving and displaying i have written in a different .m file which has to run in background of GUI. my GUI should not close during the process of receiving and displaying. i need a logic to do it.. what are all the possible ways to do it...

please help me with a solution for it..