$textfield_listing->bind('<<FocusIn>>', sub { 
	if ($textfield_listing->curselection()) {
		$button_stop->configure( -state => "normal");
		$button_log->configure( -state => "normal");
		$button_info->configure( -state => "normal");
	}
} );


$textfield_listing->bind('<<FocusOut>>', sub { 
	$button_stop->configure( -state => "disabled");
	$button_log->configure( -state => "disabled");
	$button_info->configure( -state => "disabled");

} );