Zoom Blur Effect?

I am currently trying to create an effect very similar to this http://www.flashkit.com/tutorials/Special_Effects/Zoom_Blu-Michael_-636/index.php

Now in the first frame the normal picture shows but in the last frame the blurred picture shows.

Please can someone explain how the button in the above effect is created so when the button is pressed, it goes from showing the normal picture to the blurred picture?

Please follow the link above which basically shows what i am trying to explain.

I have asked this question on the flashkit forum but haven’t got the answer which i am looking for unfortunately.

Really hope someone can explain in laymans terms.

Thank you