sf_cua_check_box    Displays the checkable font an allows user input
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    function logical sf_cua_check_box prototype
      parameters value int the_row,;
                 value int the_col,;
                 const logical the_variable

    Displays the checkable font an allows user input.  Any key will toggle
    the variable from .t. to .f. or .f. to .t., ENTER accepts the entry.

    Example:

    var = .t.
    var = sf_cua_check_box( 10, 10, var )