Why does each user have their own page? That's not a very efficient approach in most cases, though there can be reasons for setting it up that way.
You can set up an auto-enter calculation such as:
Let ( L = Get ( LayoutName ) ;
Case ( L = "BobsLayout" ; "Bob" ;
L = "TedsLayout" ; "Ted ;
"Error - Author unknown"
) // case
) // let
But if Bob and Ted each are using different account, passwords to open the database, you can also just set this field to auto-enter their account name and this will enter the current account name no matter what layout is current at the time.