Completely redraw the screen with a header.
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 Syntax

        GT_NewScreen([<cTitle>],[<cCopyRight>],<cVersion>],
                     [<cMainColour>],[<cTopColour>])

 Arguments:

      <cTitle> is the title tobe displayed centered.

      <cCopyRight> is the message to be displayed top
      left.

      <cVersion> is the version number to be displayed
      under <cCopyRight>.

      <cMainColour> is the colour pair for the main
      screen. A normal colour string may be used and the
      first pair will be extracted.

      <cTopColour> is the colour pair for the header of
      the screen. A normal colour string may be used and
      the first pair will be extracted.

 Returns:

      .T. / .F. based on success.

 Description:

      Completely redraw the screen with a header.

 Examples:

      // Blank header
      GT_NewScreen()

      // Header with info using standard colours
      GT_NewScreen( Stock Control',  ;
                    '(C) ComputAssist 1989/93', ;
                    'Rev 1.01a')

 Source: GT_NEWSC.PRG

 Author:  Martin Bryant