gui problem Error while evaluating TimerFcn for timer 'timer-160'

if true

   function frameshow_Callback(hObject, eventdata, handles)
   global t  
   global t1
t1=timer('TimerFcn',{@timerCallback1,handles},'ExecutionMode', 'fixedDelay','Period', 0.1);
guidata(hObject,handles);
stop(t);
start(t1);
if true
   function timerCallback1(hObject, eventdata, handles)
    global vid
    global t1
    global frame
      if (vid==-1)
      msgbox('show！');
      stop(t1);
      return;
      end
     axes(handles.axesshow);
      frame=getsnapshot(vid);
     imshow(frame);
       end
if true
  %function numberdetect_Callback(hObject, eventdata, handles)
global t
global t1
t=timer('TimerFcn',{@timerCallback3,handles},'ExecutionMode', 'fixedDelay','Period', 0.1);
guidata(hObject,handles);
stop(t1);
start(t);
function timerCallback3(hObject, eventdata, handles)
global vid
global t
global frame
global c
if (vid==-1)
  msgbox('first show！');
  stop(t);
  return;
end
frame=getsnapshot(vid);
imagen = rgb2gray(frame);
end
i want to use two timer to show the camera image
but i start the function sometimes shows :Error while evaluating TimerFcn for timer 'timer-160' 
but i have stop the timer than use another timer.
i recently tag error so i restart made one problem