If your are getting the error like "unknown member" then first check if
you have given correct reference to the object where you want to focus
it on the Page3. e.g. ThisFrom.Pageframe1.Pag3.Object.setfocus = .T.

If you are not sure regarding the parent refrence of the object then
in the "Page3.Active Event" click the mouse reight button, there you
will get a Object list option. Just click on it and you will get a
list of all objects which are on the form.Then just select the object
of Page3 where you want to setfocus and you will get the whole reference
to the current object as above.

I think this will solve your problem.