Interfacing .m file and GUI .m file

Hello all, I new to MATLAB GUI. I am facing difficulty in changing text of 'Edit Text' box in GUI.What I am doing based on a condition in .m script file (not GUI .m file) I want to change text in 'Edit Text' Box. I have tried with get command but not succeeded. Here is my dummy code : Please suggest some solution

% Main .m File-----------

global hu 
hu= 0;
for  i =1:10
    if i >5
        hu =1;
    else 
        hu = 0;
    end

      Change  % my gui . m file
  end

--------------------------------------------

% GUI .m file
function Change_Callback(hObject, eventdata, handles)
% hObject    handle to Change (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of Change as text
%        str2double(get(hObject,'String')) returns contents of Change as a double

global hu

if hu==1
    set(hObject,'String','OFF');
end

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I have also tried with finding object using findobj('Tag','Change') and then try to change string using set command but not found any success. here 'Change' is my Tag for edit box