ListBox(<nTop>, <nLeft>, <nBottom>, <nRight>
        [, <lDropDown>]) --> oListBox

 Arguments

     <nTop> is a numeric value that indicates the top screen row of the
     list box.

     <nLeft> is a numeric value that indicates the left screen column of
     the list box.

     <nBottom> is a numeric value that indicates the bottom screen row of
     the list box.

     <nRight> is a numeric value that indicates the right screen column
     of the list box.

     <lDropDown> is an optional logical value that indicates whether the
     list box is a drop-down list box.  A value of true (.T.) indicates that
     it is a drop-down list box; otherwise, a value of false (.F.) indicates
     that it is not.  The default is false (.F.).

 Returns

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