Matlab GUI Question

I am trying to save variables after a button push for example when I push a button in my GUI and I modify a picture I want it to remember that I did it and the next time I modify the picture it will show the new picture

Here is the function I am having trouble with

% --- Executes on button press in AddDefecct.
function AddDefecct_Callback(hObject, eventdata, handles)
%Gets information from the radio buttons 
Check(1) = get(handles.RedSubpixel,'Value');
Check(2) = get(handles.GreenSubpixel,'Value');
Check(3) = get(handles.BlueSubpixel,'Value');
Check(4) = get(handles.RedGreenSubPixel,'Value');
Check(5) = get(handles.RedBlueSubPixel,'Value');
Check(6) = get(handles.BlueGreenSubPixel,'Value');
Check(7) = get(handles.Pixel,'Value');

%Using the information from the radiot buttons to describe how to modify
%the picture
if Check(1) == 1
  Type = [1,0,0];
elseif Check(2) == 1
  Type = [0,1,0];
elseif Check(3) == 1
  Type = [0,0,1];
elseif Check(4) == 1
  Type = [1,0,0,0,1,0];
elseif Check(5) == 1
  Type = [1,0,0,0,0,1];
elseif Check(6) == 1
  Type = [0,0,1,0,1,0];
elseif Check(7) == 1
  Type = [1,1,1,1,1,1,1,1,1];                          
end
%Checks if this is the first modification
A = exist('handles.PicData','var');
if A == 0 %Checks if it is the first 
  handles.PicData = imread('BlankBoE.jpg');
end
%Adds defect and outputs the new picture data
PicData = Adddefect(Type,handles.PicData);
%Trying to save the new picture data
handles.PicData = PicData;

I guess in a nutshell I am asking how to know whether or not it is the first time this button as been pushed

Any help would be appreciated

Thanks

Steven

Answer 1

[Walter Roberson]

At the end of the callback, add

guidata(hObject, handles)

[Steven]

thx durr I am dumb