Return a blank value for the type of parameter passed.
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 Syntax

        GT_Blank( <xVar> ) --> <xBlankVar>

 Arguments:

      <cVar>        Any Clipper variable type.

 Returns:

      <xBlankVar>   A blank copy of the variable type of length of the
                    parameter.

 Description:

      Return a blank value for the type of parameter passed.

 Examples:

      GT_Blank(space(8)) --> space(8)
      GT_Blank("Phillip Hamlyn") --> space(14)
      GT_Blank( {|| "PCH" } ) --> space(3)
      GT_Blank( 123123 ) --> 0
      GT_Blank( ctod("31/08/69") ) --> ctod("")
      GT_Blank( {1,2,3} ) --> {}
      GT_Blank( TbrowseNew() ) --> NIL
      GT_Blank( TRUE ) --> FALSE

 Source: GT_BLANK.PRG

 Author:  Phillip Hamlyn