Returns a Page object representing the previous page displayed or null if there is no previous page.
A previous page always exists except when the form's first page is displayed at the start of form processing.
This is the page that will be displayed to the user when a Previous Page Button Control is clicked
or when the previous page button within a Page Navigation Panel Control is clicked.
A previous page always exists except when the form's first page is displayed at the start of form processing. This is the page that will be displayed to the user when a Previous Page Button Control is clicked or when the previous page button within a Page Navigation Panel Control is clicked.