Enabling a Button on my ABAP Web Dynpro after reading imbedded Smartform.

Hi:

How would I go about enabling a Button on my ABAP Web Dynpro after the user has read the imbedded Smartform? Basically I have a Smartform in an Interactive Form on the UI. After the reader scrolls to the bottom of the Smartform, I want the "Agree to Contents" button to be enabled, so that the User implies that they have read the 5 page document.

Thanks,

MG