jarich, thank you for your reply.

i pasted your code in my $SIG{'__DIE__'} adn here is it.

local $SIG{'__DIE__'} =
sub
{
    my $my_today_int = $today_int;
    my $my_no_call_requested_days = $no_call_requested_days;
    my $my_i = $i;
    my $my_user_id = $user_id;
    my @dump = ();

    # Just grabbing the values of these so that
    # strict will cope with them.
    push @dump, $_[0], "";
    push @dump, Dumper($my_today_int, $my_i, $my_user_id), "";
    push @dump,  Dumper($my_no_call_requested_days), "";
    {
        use strict;
        my @today = @{$my_no_call_requested_days->{$my_today_int}};
        push @dump,   "today: " . Dumper(@today), "";

        my $ref = $today[$my_i];
        push @dump,  "ref: " . Dumper($ref), "";

        my $employee_id = $ref->{'employee_id'};
        push @dump,  "employee_id: [$employee_id]", "";

        if($employee_id eq $my_user_id)  # should be "=="
        {
            push @dump,  "They are the same!", "";
        }
    }
    &debug(@dump);
};
[download]

Here is the output.

Can't use an undefined value as a HASH reference at /usr/local/www/cgi
+-bin/kapc/md2/display_md_calendar.cgi line 1534.

$VAR1 = 1041483600;
$VAR2 = 0;
$VAR3 = '0';

$VAR1 = {
 '1050120000' =>
    [ { 'employee_id' => '34', 'type' => 'Routine' } ],

 '1049173200' =>
    [ { 'employee_id' => '28', 'type' => 'Routine' } ],

 '1043211600' =>
    [ { 'employee_id' => '0', 'type' => 'Hospital' },
      { 'employee_id' => '34', 'type' => 'Routine' }
    ],

 '1043989200' =>
    [
      { 'employee_id' => '16', 'type' => 'Routine' },
      { 'employee_id' => '10', 'type' => 'Routine' }
    ],

 '1043125200' =>
    [ { 'employee_id' => '27', 'type' => 'Routine' } ],

 '1051329600' =>
    [
      { 'employee_id' => '24', 'type' => 'Routine' },
      { 'employee_id' => '16', 'type' => 'Routine' }
    ],

 '1051243200' =>
    [
      { 'employee_id' => '24', 'type' => 'Routine' },
      { 'employee_id' => '16', 'type' => 'Routine' }
    ],

 '1041483600' =>
    [
      { 'employee_id' => '27', 'type' => 'Routine' },
      { 'employee_id' => '27', 'type' => 'Routine' }
    ],

 '1058932800' =>
    [ { 'employee_id' => '23', 'type' => 'Routine' } ],

 '1053144000' =>
    [ { 'employee_id' => '20', 'type' => 'Routine' } ],

 '1043298000' =>
    [ { 'employee_id' => '0', 'type' => 'Routine' } ],

 '1046149200' =>
    [
      { 'employee_id' => '23', 'type' => 'Routine' },
      { 'employee_id' => '28', 'type' => 'Routine' }
    ],

 '1046322000' =>
    [ { 'employee_id' => '28', 'type' => 'Routine' } ], 

 '1046408400' =>
    [ { 'employee_id' => '10', 'type' => 'Extension' } ],

 '1048222800' =>
    [
      { 'employee_id' => '28', 'type' => 'Routine' },
      { 'employee_id' => '10', 'type' => 'Routine' }
    ],

 '1045198800' =>
    [
      { 'employee_id' => '28', 'type' => 'Routine' },
      { 'employee_id' => '13', 'type' => 'Routine' },
      { 'employee_id' => '13', 'type' => 'Routine' }
    ],

 '1048136400' =>
    [ { 'employee_id' => '28', 'type' => 'Routine' } ],

 '1042693200' =>
    [ { 'employee_id' => '0', 'type' => 'Routine' } ],

 '1045285200' =>
    [ { 'employee_id' => '0', 'type' => 'Routine' } ],

 '104400' =>
    [
      { 'employee_id' => '16', 'type' => '-Routine' },
      { 'employee_id' => '10', 'type' => '-Routine' },
      { 'employee_id' => '28', 'type' => '-Routine' },
      { 'employee_id' => '13', 'type' => '-Routine' },
      { 'employee_id' => '13', 'type' => '-Routine' },
      { 'employee_id' => '10', 'type' => '-Extension' },
      { 'employee_id' => '28', 'type' => '-Routine' },
      { 'employee_id' => '10', 'type' => '-Routine' },
      { 'employee_id' => '24', 'type' => '-Routine' },
      { 'employee_id' => '16', 'type' => '-Routine' }
    ],

 '18000' =>
    [
      { 'employee_id' => '16', 'type' => '-Routine' },
      { 'employee_id' => '10', 'type' => '-Routine' },
      { 'employee_id' => '28', 'type' => '-Routine' },
      { 'employee_id' => '13', 'type' => '-Routine' },
      { 'employee_id' => '13', 'type' => '-Routine' },
      { 'employee_id' => '10', 'type' => '-Extension' },
      { 'employee_id' => '28', 'type' => '-Routine' },
      { 'employee_id' => '10', 'type' => '-Routine' },
      { 'employee_id' => '24', 'type' => '-Routine' },
      { 'employee_id' => '16', 'type' => '-Routine' },
      { 'employee_id' => '0', 'type' => '-Routine' },
      { 'employee_id' => '34', 'type' => '-Routine' },
      { 'employee_id' => '24', 'type' => '-Routine' },
      { 'employee_id' => '16', 'type' => '-Routine' },
      { 'employee_id' => '20', 'type' => '-Routine' }
    ],

 '-154800' =>
    [
      { 'employee_id' => '0', 'type' => '-Routine' },
      { 'employee_id' => '34', 'type' => '-Routine' },
      { 'employee_id' => '24', 'type' => '-Routine' },
      { 'employee_id' => '16', 'type' => '-Routine' },
      { 'employee_id' => '20', 'type' => '-Routine' }
    ],

 '1045717200' =>
    [ { 'employee_id' => '23', 'type' => 'Routine' } ]
};

today: $VAR1 = { 'employee_id' => '27', 'type' => 'Routine' }; $VAR2 =
+ { 'employee_id' => '27', 'type' => 'Routine' };

ref: $VAR1 = { 'employee_id' => '27', 'type' => 'Routine' };

employee_id: [27]
[download]

Here is the line 1534 where the script dies.

if (%{@{$no_call_requested_days->{$today_int}}[$i]}->{'employee_id'} =
+= $user_id)
[download]