How to move up/down the row element in a ListBox/Mlistbox

[ghosh123]

Hi Monks, I need one push in regard to move a row element up and down by clicking a button or pressing Up/Down key. Let us consider this small code below ================================================

my $mw = MainWindow -> new();

my $lb = $mw -> Scrolled("Listbox",

    -scrollbars=>'e' ,
    
) -> pack(

    -side => 'left' ,
    -fill => 'y'
);

foreach my $key ("first" , "second" , "third", "fourth") {
    
    $lb -> insert( 'end', $key );

}

    $lb->activate ( 0 ) ;
    $lb->selectionSet ( 0 ) ;
    $lb->focus;

$lb -> bind ('<Key-Down>', sub {print "Down\n"} );

$mw -> bind ('<Key-Up>', sub {print "\nUP"} );

MainLoop;

================================================== Now the items appear as "first", "second" ,"third" and "fourth" in row1 row2,row3 and row4 respectively. My requirement is to alter the order of appearence by clicking or pressing up/down key. For example after the order would appear as "second" "first" "fouth" and "third". Kindly help . Thanks in advance. -AG