Simple LWP'ing and parsing

Hi.

Temporary goal: being able to "perl script.pl ARGV" and script downloads website-content (HTML) specified in script where ARGV represents query in website (i.e. the query for Google would be: search?q=ARGV), and filters out/only print out some text-parts from the website I want.

Actual work/website/template chosen:
URL: Mestera
(1 of 3) Part(s) with crucial information (HTML): <tr><td>Attack: </td><td><span style='font-weight: small; color: yellow;'>16</span></td></tr>
Wanted text printed from the above: Attack: 16

Status:
First I tried Regex. That's worked for me earlier with LWP.
Failed. I forgot why, I just gave up, didn't work for me.
So I Google some and figure HTML::TreeBuilder sounds fair enough & possibly more suitable.
I use code from demonstrations I understand and agree with =_=
But doesn't work.
Now, the current code is:

use LWP;
use HTML::TreeBuilder;

my $tree = HTML::TreeBuilder->new;
my $ua = LWP::UserAgent->new;
my $request = $ua->get("http://www.mestera.net/wikia_view_item_info.php?name=$ARGV[0]");
my $response = $request->decoded_content;
my $response = $tree->parse($response);
my @info = $tree->look_down('_tag', 'span style' => 'font-weight');
for my $info (@info) {
 print $info->as_trimmed_text();
}

This line:

my @info = $tree->look_down('_tag', 'span style' => 'font-weight');

gives me:

Quote

param list to look_down ends in a key! at lwp2.pl line 9

If it instead sound:

my @info = $tree->look_down('span style' => 'font-weight');

I'm returned nothing (blank result, returned to terminal prompt)
And I tried more variations, like: look_down('_tag', span style => 'font_weight');
etc
And more... and more...

Suggestions/solution anyone?
And better yet, how do I solve these things myself? I've honestly been sitting pondering this one for hours already, Googling and quickly-read through about 20-35 articles on the subject, with no solution. Maybe I should've read more about HTML Element, but =_= I think it's really quite silly how I have to go through all of this for simply getting the information between these <span></span> tags.
Jesus. I love Perl for making easy things easy, when they indeed do so.
I hate all programming for making anything hard; or worse yet - and the real problem being, making anything impossible to understand with mere logic.
I wish EVERYTHING was dictated by common sense, only on different levels of difficulty. Never "senseless, but works" - that's so silly to me..
*Want some frustration off my back :@*

Edit: solved. I guess I was (too) tired and frustrated ;)
This code got the values I wanted:

use LWP;
use HTML::TreeBuilder;

my $tree = HTML::TreeBuilder->new;
my $ua = LWP::UserAgent->new;
my $request = $ua->get("http://www.mestera.net/wikia_view_item_info.php?name=$ARGV[0]");
my $response = $request->decoded_content;
my $response = $tree->parse($response);
my @info = $tree->look_down('_tag', 'span',
sub { $_[0]->attr('style') =~ /font-weight: small;/ }
);
for my $info (@info) {
 print $info->as_trimmed_text();
}

Dunno what $_[0] means, or if/how it's different from just _$ -- I'll probably search for this soon enough and find out...
Also: this isn't exactly a very practical solution.
What do I do now if I want two tags instead..? two subs? two seperate look_down's? same sub separated by comma or/and newline?

Edit2: I see I'm lucky in this case and can just do:

my @info = $tree->look_down(
'_tag', 'table',
sub { $_[0]->attr('width') eq '40%' }
);

But if anyone reading this post/thread and thinking "how can I help this guy?", I still wanna know 1) how I'm supposed to figure stuff like this out (but a case that is harder to figure out/find information about) in the future, except for excessive Googling, only hoping that SOME newb like myself has issued my problem -- cus all of these methods (like entirely how the look_down works) isn't mentioned @ cpan.org documentation, and 2) how would I solve this if I hadn't just been lucky that the table with a unique 40% width had exactly, and only exactly the information I was looking for?
And with use strict&warnings, I get this warning 6x:

Quote

Use of uninitialized value in string eq at lwp2.pl line 13.

I feel like I don't stand a chance @ programming:D

Edited by Mentalbox, 25 June 2011 - 04:36 PM.
specifically, but not generally solved