pcxResH()

         Returns the horizontal resolution of the PCX

    Syntax:

         pcxResH ( cFile ) -> nResH

         cFile : Name of the PCX file

    Description:

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

    Return:

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

    Example:

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