FILESCREEN()
 Reads screen content from a file
------------------------------------------------------------------------------
 Syntax

     FILESCREEN(<cFileName>, [<nOffset>]) --> nByte

 Arguments

     <cFileName>  Designates the name and path of the screen file.

     <nOffset>  Designates from which part of the file offset the screen
     is to be read.  The default is the beginning of file.

 Returns

     FILESCREEN() returns the number of bytes read.

 Description

     FILESCREEEN() is the opposite of SCREENFILE().  Use FILESCREEN() to read
     and display a screen stored with SCREENFILE().  Use the <nOffSet>
     parameter to indicate an offset from which the file is to be read.
     Since the number of bytes written with SCREENFILE() is known, you can
     compute the location within the file of the beginning of the new screen.
     This allows you to save multiple screens in a single file.

 Note

     .  The file read with FILESCREEN() can also contain end of file
        markers.  The read procedure does not end prematurely as a result,
        since the function always reads 4000 bytes.

 Examples

     .  Read a screen from the beginning of a file:

        FILESCREEN("screen.tst")

     .  Read the second screen.  Since the offset is specified as
        4000, the first screen is skipped:

        FILESCREEN("screen.tst", 4000)

     .  Drive and path are permitted:

        FILESCREEN("\screen.tst")
        FILESCREEN("a:screen.tst")

     .  Wildcards are not permitted:

        FILESCREEN("screen.*")         // Result:  0