var
 QS_liste: Array[1..10] of integer;
 l_pos, r_pos, pivot, temp, pivot_feld : integer;
{...}
procedure Quicksort(var a: array of integer; anfang, ende:integer);
var i: integer;
begin
      pivot_feld := (anfang+ende)div 2;
      pivot := a[pivot_feld];

      l_pos := anfang;
      r_pos := ende;
      repeat
            while a[l_pos] < pivot do inc(l_pos);
            while a[r_pos] > pivot do dec(r_pos);
            if l_pos < r_pos then begin

                      temp := a[l_pos];
                      a[l_pos] := a[r_pos];
                      a[r_pos] := temp;

                      inc(l_pos);
                      dec(r_pos);
                      end;
       until (l_pos > r_pos) ;

       if (anfang < r_pos) then quicksort(a, anfang, r_pos);
       if (l_pos < ende) then quicksort(a, l_pos, ende);
end;