Hello monks,

I'm writing an analysis program where I need to make a series of selections before the proces can start. For that I have several listboxes. Unfortunately, if I make a selection in the second listbox, the selection in this first one disappears. What do I do incorrectly?

The code attaches is not the simplest possible, but is a minimal version of my problem-code. It has two listboxes, and I want the selection in the top one to stay selected when I make a selection in the bottom listbox.

Any suggestions? Thank you! 
#!/usr/bin/perl 

use strict;
use Tk;
my $mw         = MainWindow->new;
my $gui_period = $mw->Scrolled(
    qw/Listbox
      -height 5
      -width 20
      -background white
      -selectforeground red/
);
my $gui_report = $mw->Scrolled(
    qw/Listbox
      -height 5
      -width 20
      -background white
      -selectforeground blue/
);
$gui_period->grid( -row => 0, -column => 0, -rowspan => 1, -sticky => 
+'nsew' );
$gui_report->grid( -row => 1, -column => 0, -rowspan => 1, -sticky => 
+'nsew' );

$gui_period->bind( '<ButtonRelease-1>' => \&show_period );
$gui_report->bind( '<ButtonRelease-1>' => \&show_report );

my ($item);
my @periodlist = qw/one two three four/;
foreach $item (@periodlist) {
    $gui_period->insert( 'end', $item );
}
my @reportlist = qw/first second third fourth/;
foreach $item (@reportlist) {
    $gui_report->insert( 'end', $item );
}

MainLoop;

sub show_period {
    my @index = $gui_period->curselection();
    my $index = $index[0];
    $gui_period->selectionSet($index);
    print "period: $index $periodlist[$index]\n";
}

sub show_report {
    my @index = $gui_report->curselection();
    my $index = $index[0];
    $gui_report->selectionSet($index);
    print "report: $index $reportlist[$index]\n";

}

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In reply to simultaneous selections in Tk by momo33

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