Help delayed button action

Hello there

I have a problem that I, a newbie that discovered this whole mit app inventor ordeal yesterday, haven't been able to solve, even thought I spent quite a while searching for a solution.

What I want to do is when I click a button there is a delay, in this case of twenty seconds, until the button does its action, that is to change from screen1 to screen2.

Could anyone help me?

You use the clock timer:

blocks (7)

Use different screens wisely

If you decided to use different screens, then you should switch them correctly, else you will run out of memory after a while...      
The recommended method of switching screens in App Inventor
(Thanks Taifun)
Also see demo: multiscreen.aia