function TMyChek.MyChekGleich(StringGrid:TggStringGrid; SpaltenNr:Integer):Integer ;
var
  a , b ,c : integer;
  Inhalt_Check : string;
  iDoppeltcounter:integer;
begin

  iDoppeltcounter:=0;
  Result:=-3;
  b:= StringGrid.RowCount;


  for a:=0 to b-1 do begin
    Inhalt_Check:=StringGrid.Cells[SpaltenNr,a];
     for c:=a+1 to b-1 do begin
        if Inhalt_Check=StringGrid.Cells[SpaltenNr,c] then begin
           Inc(iDoppeltcounter);
             if iDoppeltcounter>1 then begin
                 Result:=c;
                 //StringGrid.Selection:= ??
                 exit;
                 iDoppeltcounter:=0;
             end;
        end;
     end;
  end;
end;