GUI - How to interrupt an endless loop with another callback

Hello, I have some truble interrupting an animation in a GUI I wrote. The loop gets called by some Button1 like this

sd = 1;
loop_running = true;
KW=0;
axes(handles.axes1)
while loop_running

      if KW+sd>size(KnM,3)
          sd=-1;
      elseif KW+sd==0
          sd=1;
      end;
      KW = KW+sd;

      scatter3(scatter information);
      axis([0 0.2 -0.1 0.1 -0.1 0.1])

      handles.KW = KW;
      set(handles.edit8,'String',num2str(KW));
      guidata(hObject,handles);
      pause(PauseTime);

      if isfield(handles,'Pause')
          if handles.Pause
              break;
          end;
      end;
      %loop_running=handles.loop_running;
  end;

Then there is my Pause Button

global test
if isfield(handles,'Pause')
    if handles.Pause
        handles.Pause = false;

      else handles.Pause
          handles.Pause=true;

      end;
  else
      handles.Pause = true;

end;
test=1;
guidata(hObject,handles);

Button1 is interruptible, so when PauseButton is clicked, at pause(PauseTime); the PauseButton script runs, creates the handles.Pause field, BUT gets kinda deleted right afterwards, so the if isfield(handles,'Pause') is always false. I also tried to set loop_running=false with the same result. Its just like the callback of PauseButton never happens even though when debugging I can see the handles.Pause is created, but just as well beeing deleted right afterwards(same with that global variable I tested). The other answers I found, had a similar scipt or way to approach interrupting a loop.

Can somebody tell me what Im missing?

Many thanks in advance!! :)

Answer 1

[Mr Anderson]

UPDATE:

I just forgot to set the global test variable in my Button1 Callback, so the break using a global variable works fine.

But since global variables are bad, I'd still appreciate any help to use the handles Struct, or telling me what i did wrong.

Thanks :)