pcxResV()

         Returns the vertical resolution of the PCX

    Syntax:

         pcxResV ( cFile ) -> nResV

         cFile : Name of the PCX file

    Description:

         This function returns the vertical resolution of the PCX file if
         it exists and has a PCX format. Else returns Nil.

    Return:

         The vertical resolution or Nil if the file does not exist or it
         is not a PCX.


    Example:

         ? pcxResV ( "c:\fast\lib\fast.pcx" )