You need to declare the variable before usage. Try: 
my $counter = 0;
# (comment-out added): use vars qw($counter);

[download]
or (From davido) 
use vars qw($counter);
$counter = 0;

[download]
-jbWare

Update: Per davido's comment, I've modified my answer.

In reply to Re: perl doesn't like variable by jbware
in thread perl doesn't like variable by jamaas

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