sub num_month 
{
  my $date_line = shift; #like jan 12 2009 or january 12 2009
    
  my %months  = (JAN => '01', FEB => '02', MAR => '03', 
                APR => '04', MAY=> '05', JUN => '06', 
		JUL => '07', AUG => '08', SEP => '09', 
		OCT => '10', NOV => '11', DEC => '12',
		JANUARY => '01, ....etc.....);
				
  my (@tokens) = split (/\s+/, uc($date_line));
  foreach my $token (@tokens)
  {
     return ($months{$token} if $months{$token});
  }
  die "no month in @tokens";  ## optional but you may want this
}