MARC.pm unblessed reference

[Aaron Huber]

Hi All,

I am a complete newbie to this and have been testing out  MARC.pm. 
I'm trying to return just the ISBN values from a group of MARC
records. It works fine when I specify the record number, but when I
put it through the loop it returns the above error.

Can't call method "getvalue" on unblessed reference at
/usr/pkg/lib/perl5/vendor_perl/5.8.0/MARC.pm line 550, <file> line 4.

Here's the my code:

use MARC;

$x = new MARC;
$n = $x->openmarc({file=>"marc.dat",'format'=>"usmarc",
                  increment=>"-1"});

print "Retrieved $n records.\n";

foreach $i (1..$n)  {
        $isbn = $x->getvalue({record=>'$i',field=>'020'});
        print "$i: $isbn\n";
        }

Thanks,
Aaron S. Huber
Librarian I
Broward County, FL