Plotting with two y-axes in a GUIDE GUI

I have a simple GUI created in GUIDE with two axes (axes1, axes2) and a pushbutton (pushbutton_plot).

The callback for pushbutton_plot is the following:

% --- Executes on button press in pushbutton_plot.
function pushbutton_plot_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton_plot (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

% data
x = 0:pi/100:10*pi;
y = sin(x);
z = cos(x);
w = x./x;

% loop
n = numel(x);

% axes1 plot
h(1) = plot(handles.axes1, x(1), y(1));

h(2) = plot(handles.axes1, x(1), z(1));

% axes2 plot
h(3) = plot(handles.axes2, x(1), w(1));

for i = 1:n-1

      % axes1
      set(h(1), 'XData', x(1:i), 'YData', y(1:i));

      set(h(2), 'XData', x(1:i), 'YData', z(1:i), 'color', 'green');

      % axes2
      set(h(3), 'XData', x(1:i), 'YData', w(1:i), 'color', 'red');

      drawnow;
      pause(1/10);

end 
hold off

The plots are done like this so the graphs appear to be plotting in real-time. This syntax works when I'm using figures, but I can't get two lines to plot in one axes (with two y-axes) in GUIDE.

The error says I have an "invalid or deleted object" and refers to the line

set(h(1), 'XData', x(1:i), 'YData', y(1:i));