how to write If-else statement in GUI Matlab?

hi, I would like to display massage box on a GUI screen based on value of 'sum' operation. i have 2 editBox and user need to enter 2 value on those box. then, i will click on pushbutton called "SUM". based on the answer, if the value is between 0-0.5, the massage box will display "INSECURE". if the answer is between 0.6-1.0, the massage box will display "HIGH". i have write some coding but it can't RUN. can anyone help me? Thanks

% --- Executes on button press in sumbutton.
function sumbutton_Callback(hObject, eventdata, handles)
% hObject    handle to testingbutton (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
val = str2num(get(handles.input1,'String')) + str2num(get(handles.input2,'String'));
if (val >= 0 && val <= 0.5)
  msgbox('Your System is INSECURE')
if  (val >= 0.6 && val <= 1)
  msgbox('Your System is SECURE')

Answer 1

[Azzi Abdelmalek]

   % --- Executes on button press in sumbutton.
function sumbutton_Callback(hObject, eventdata, handles)
% hObject    handle to testingbutton (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
val = str2num(get(handles.input1,'String')) + str2num(get(handles.input2,'String'));
if (val >= 0 && val <= 0.5)
    msgbox('Your System is INSECURE')
elseif  (val >= 0.6 && val <= 1)
    msgbox('Your System is SECURE')
end

You need to read the help http://www.mathworks.com/help/matlab/ref/if.html

[Ahmad Farhan]

thank u.. i thought the way i write the 'expression' is wrong..