Hello kanthsri, and welcome to the Monastery!

I re-formatted your code as follows:

#! perl
use Modern::Perl;
use LWP::Simple;
use URI::Escape;
use HTML::TreeBuilder;
use Try::Tiny;

my $look_for = "perl";
my $contents = get "http://www.amazon.com/s/ref=nb_sb_noss?url=search-
+alias%3Dstripbooks&field-keywords=" . uri_escape($look_for);
my $html     = HTML::TreeBuilder->new_from_content($contents);

for my $item ($html->look_down(id => qr/result_\d+/))
{
    # $item->dump;
    # find out structure of HTML
    my $author = try { $item->look_down(class => 'ptBrand')->as_trimme
+d_text };
    print "$author\n";
}

$html->delete;

[download]

and ran it with the following result:

16:54 >perl 452_SoPW.pl
by Randal L. Schwartz, brian d foy and Tom Phoenix
by Tom Christiansen, brian d foy, Larry Wall and Jon Orwant Ph.D.
by Tom Christiansen and Nathan Torkington
by Randal L. Schwartz, brian d foy and Tom Phoenix
by Johan Vromans
by Joseph N. Hall, Joshua A. McAdams and brian d foy
by Randal Schwartz, Tom Phoenix and brian d foy
by David N. Blank-Edelman
by brian d foy
by Curtis Poe
by Damian Conway
by Paul E. Hoffman

16:56 >

[download]

What output do you get? In what way is the code “not executing” in your system?

Update: Just realised that the title answers my question! What version of HTML::TreeBuilder are you running? Mine is v5.01. What is line 108 in your version of this module?

Athanasius <°(((>< contra mundum Iustus alius egestas vitae, eros Piratica,

In reply to Re: Use of uninitialized value in subroutine entry at C:/Perl/lib/HTML/TreeBuilder.pm line 108. by Athanasius
in thread Use of uninitialized value in subroutine entry at C:/Perl/lib/HTML/TreeBuilder.p m line 108. by kanthsri

Title:
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