(* Ask user to choose a .pages file. *)
tell application "System Events"
    activate
    set n to ""
    try
       repeat while n does not end with ".pages"
          set file_name_alias to choose file with prompt "Please select a .pages file"
          tell disk item (file_name_alias as text)
        set n to name
        set d to path of container
          end tell
       end repeat

    on error -128 -- user cancelled
        return
    end try
end tell