waitbar interference plot settings in GUI

I'm trying to plot all six curves in one plot in a simple GUI. but it stopped working after I add a statusbar, namely the waitbar function. I dont know why. any help appreciated.

function gui_test
fh = figure('Visible','on','position',[50,60, 660, 400]);
hax = axes('Units','pixels','Position',[60,90,400,300],'color','black');
hpb1 = uicontrol('Style','pushbutton','String','RUN',...
  'position',[500 200, 80, 40],'Callback',{@run_Callback});

    function run_Callback(source,eventdata)

        h = waitbar(0,'Please wait...');

        for i=1:6, 
            % update waitbar       
          waitbar(i/6,h,'computing time a Min');
            x=0:0.00001:10;

            y = sin(i*0.2.*x).*cos(0.3.*x);
            hold on;
            plot(hax,x,y);

        end
        close(h);  
    end
end