Tapping experiment - GUI help

I am designing a tapping experiment in order to get the tempo of a song. The listner listens first 3 seconds of the song and then starts tapping using mouse or keyboard. The tap-interval is recorded to get the tempo. I want the GUI to display Start tapping in 3, 2 1 sec. How do I do that?

[Dennis]

You can do it like this:

handles.tb=uicontrol('style','text','position',[200 100 200 40]); %create a textbox
for i=10:-1:1
    handles.tb.String=sprintf('Start in %d',i); %change string of textbox (2013 or older matlab versions require different synthax)
    pause(1)
end

The time between each number decrease will be a few milliseconds longer than 1 second though.