use Tk;

my $top = new MainWindow();
my %density = (A=>1,B=>2,C=>3);
my $row = 0;
foreach (sort keys(%density)) {
	my $keytext = $top->Label(
		-height=>1,-width=>10,-text=>$_,-justify=>'left')->grid(-row=>$row,-column=>0);
	my $denbox = $top->Entry(
		-textvariable=>\$density{$_},-width=>5)->grid(-row=>$row,-column=>1);
	$row++;
}

MainLoop();