CheckBox(<nRow>, <nColumn>,
        [,<cCaption>]) --> oCheckBox

 Arguments

     <nRow> is a numeric value that indicates the screen row of the check
     box.

     <nColumn> is a numeric value that indicates the screen column of the
     check box.

     <nCaption> is an optional character string that describes the check
     box on the screen.  If omitted, the default is an empty string.

 Returns

     Returns a CheckBox object when all of the required arguments are
     present; otherwise, CheckBox() returns NIL.