call a gui

hello everybody I'm french so excuse me for my english. I have a problem, I want to call a windows when I check a checkbox :

function diff_Callback(hObject, eventdata, handles) global open; global R; Tdiff®;

Tdiff is an other gui defined like this : function [T,varargout] = Tdiff( R )

I got this error : ??? Undefined variable varargin.

I've tested with varargin instead of R but it doesn't work. R is a matrice of cell :

R =

    [1x27 char]    [1x27 char]    [1x25 char]    [1x28 char]

thank you for your help