my $run_all_btn=$mw->Button(
	-text => 'run all',
	-width => 20,
	-height => 2,
	-activebackground => 'red',
	-background => 'green',
	-command => sub {
	        $run_job1->invoke();
		$run_job2->invoke();
		$run_job3->invoke(); #I want the button freeze until run completion of all buttons job1, 2 and 3.
        })->pack();
        $run_all_btn->flash(); #seem not working