procedure TForm1.hatVerschluesselnClick(Sender: TObject);
var Str1, Str2: String;
begin
  Case hatCalgorithmen.ItemIndex of 0: begin
                                         Str1:=hatMplain.Text;
                                         Str2:=hatMcipher.Text;
                                         setLength(Str2,length(Str1));
                                         hatRC4.RC4Init(hatRC4,'Passwort');
                                         hatRC4.RC4Code(hatRC4, Str1[1], Str2[1], Length(Str1));
                                       end;
  end;
end;