How to control the LED flashing and extinguish it where in a loop! I hope that i can stop it with another pushbutton callback

function pushbutton1_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton1 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

set(handles.activex4,'value',0);

for i=1:9999
    if mod(i,2)==1
    set(handles.activex3,'value',1); 
    pause(0.5); 
    else
    set(handles.activex3,'value',0);
    pause(0.5);
    end   
end

Answer 1

[Walter Roberson]

if get(handles.activex4, 'Value') ~= 0
  break
end