Font()

         Changes the font of characters

    Syntax:

         Font( cFile ) -> nError

         cFile : The filename with the font

    Description:

         It changes the pointer to the Bios zone, where the character
         font is placed, to a new character font place in memory to be
         used.

    Return:

         A numeric value indicating:

                0       Ok
               -1       The file does not exist
               -2       File structure is incorrect

    Example:

         If Empty( Font ( "c:\os2\mdos\myappl\fonts\roman.fon" ) )
           ? "Ok"
         EndIf