Document Setup  
    Use Document Setup to change the page size of the active
 document  or to switch between a single-sided and facing-page
 document. 
    When a new document is created, page margins are determined by
 the Page Size and Margin Guides specified in the New dialog box.
 If Automatic Text Box is checked, an automatic text box coinciding
 with the page margins is created on the first page of the document and
 on the original master page. 
    Double Sided Pages is always available for a single-sided
 document, and for a double sided  page document that has no double
 sided master pages and no pages on which the blank double-sided page
 master has been applied.