Display a message in a box on the screen
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 Syntax

        GT_Message(<cText>,[<cTitle>],[<cColour>], ;
                   [<cBoxLines>],[<nTop>],[<nLeft>],[<nBottom>], ;
                   [<nRight>]) => lSuccess

 Arguments:

      <cText> is the message to display.

      <cTitle> is an optional title for the box.

      <cColour> is an optional colour string.

      <cBoxLines> are the optional box lines to use.

      <nTop>,<nLeft>,<nBottom>,<nRight> are the
      corners of the box. As many or  as few of these may
      be used as required. The default is to centre the
      message.

 Returns:

      .T. / .F. based on the success.

 Description:

      Display a message in a box on the screen

 Examples:

      // Message centered on the screen
      GT_Message('Hello?')

      // Fix top left
      GT_Message('Hello?',NIL,NIL,NIL,05,10)

 Source: GT_MESSA.PRG

 Author:  Martin Bryant