my @jobs = qw( 18L 07O and so on );
my @checks = ('NOT CHECKED') x @jobs;
my @buttons;
my $i = 0;
for (@jobs)
{
    my $buttons[$i] = $check_frame->Checkbutton
    (
        -text => $_,
        -variable => \$checks[$i],
        -onvalue => '    ADDED',
        -offvalue => 'NOT CHECKED',
        -command => print OUTFILE "$jobs[$i]\n"
    )->pack();
    $i++;
}