$mw->bind('<ButtonPress>' =>
        sub {
                $x_begin = $Tk::event->x;
                $y_begin = $Tk::event->y;
                print "x_begin = $x_begin y_begin=$y_begin\n";
                $mw->bind('<Motion>' =>
                        sub {
                                $x_now = $Tk::event->x;
                                $y_now = $Tk::event->y;
                                print "x_now = $x_now y_now=$y_now\n";
                                $rec = $chart->createRectangle(
                                    $x_begin, $y_begin, 
                                    $x_now, $y_now, -width => 2, 
                                    -outline => 'yellow',
                             ###################            
                                 -tags => ['rect'] );
                             ###################
                                $rec2 = $chart2->createRectangle(
                                      $x_begin, $y_begin,
                                      $x_now, $y_now, -width => 2, 
                                      -outline => 'orange',
                                #################    
                                 -tags => ['rect'] );
                                ##################
                        });
        }
);


$mw->bind('<ButtonRelease>' => sub {
               print "ButtonReleased\n"; #$chart->delete($rec);
                        $mw->bind('<Motion>', "");
                        $chart_width = $chart->width;
                        $chart->delete($rec);
                        $chart2->delete($rec2);
######################################
                        $chart->delete('rect');
                        $chart2->delete('rect');
######################################
                        $d = $x_begin/$chart_width;
                        $e = $x_now/$chart_width;
              print "draw next chart at $d percent of timeline, 
                           end at $e percent of timeline\n";
                        $chart->clearchart;
                        $chart2->clearchart;
                        &update_data($d, $e);
                        $chart->plot(\@data);
                        $chart2->plot(\@data2);

                 }
);