WBOARD()
 Allocates allowable screen area for windows
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 Syntax

     WBOARD([<nTopRow>, <nLeftColumn>, <nBottomRow>,
        <nRight Column>]) --> nError

 Arguments

     <nToprow>, <nLeftcolumn>, <nBottomrow>, <nRightcolumn>  Designate
     the screen coordinates (upper left and lower right) within which windows
     can be opened.

     ()  If WBOARD() is called without parameters, then the window border is
     reset to the boundaries of the physical screen, which as a rule
     corresponds to a call of WBOARD(0, 0, 24, 79).

 Returns

     WBOARD() returns a -1 if an error occurs.   If no errors occur, WBOARD()
     returns a 0.

 Description

     This function defines the screen area where windows are permitted.
     Windows are subsequently only visible in this defined area.  You can use
     this function to protect an area of the screen from being overwritten
     with windows, even when you allow the user to move the window
     interactively.  The boundaries designated by WBOARD() become the screen
     boundaries for window functions.

 Notes

     .  WBOARD() is only effective when there are no open windows.

     .  Always consider that closing individual windows or all the
        windows never influences the setting of the window border.  So if you
        neglect to specifically eliminate the window border, you can have
        unanticipated problems later when you open windows.

 Example

     Leave only the upper half of the screen free for window functions:

     WBOARD(0, 0, 12, 79)