Dynamic Request Page for reports?

We are in the midst of an upgrade from 3.7B to NAV2013. I have some processing reports to upgrade that make use of dynamic request forms in 3.7B. Basically, the old request form would have business logic that controlled whether certain Controls were editable or not.

Example: If you check "Update Location Code" as true, a separate Control linked to the location table would become editable.

Is this still possible with request pages? All I can find in the symbol menu is a general request page editable property. It does not seem to exist at the Control level.

I thought it might be easily analogous to 3.7B, but the below does not compile.

IF NOT bUpdateLocation THEN BEGIN
  CLEAR(sUpdateLocation);
  RequestOptionsPage.NewLocation.EDITABLE(FALSE);
END ELSE
  RequestOptionsPage.NewLocation.EDITABLE(TRUE);