Adding new screen to object repository with child windows

I have a existing script. We have a new release which has an enhanced screen.. for example registration page has some new fields. some of them are drop down and some user input fields. My Doubt is if I Just Add the new screen to the object repository with all it's child windows will the same script work? or should I make any more changes. Also should I go about deleting the old screen object from the object repository?

[B]Question asked by visitor Guna[/b]

There is an option in Object Repository wherein you can add specific objects & get them recognised explicitly