I have a list ID codes (UniProt Codes). Each code representative of a protein. There is website called InterPro that is used to deal with proteins related information. URL for that website contains that particular code. By changing that code in that URL I can get information about any protein. I wrote a program that can retrieve HTML page from the url and the retrieve information written under the heading of "protein family membership". I did this usinf HTML::treebuilder. Code is written below:

 use LWP::Simple;
use HTML::TreeBuilder;

my @ports=qw(
P23141
P61177
P60725
P30542
P21817
P29274
Q07343
P08172
P20309
Q9GZZ6
);

for (my $i=0;$i < scalar(@ports);$i++) {
my $url= "http://wwwdev.ebi.ac.uk/interpro/ISearch?query=".$ports[$i].
+"+";
my $resp = get( $url );

my $tree = HTML::TreeBuilder->new_from_content($resp);
my $first=$tree->look_down(_tag => 'div',class => 'prot_fam');
$first=$first->look_down(_tag => 'div',class => 'entry-parent');
$first=$first->look_down(_tag => 'div',class => 'entry-parent');
$first=$first->look_down(_tag => 'a');
open (FH,">>result.txt");
print FH $ports[$i].";";
print FH $first->content_list;
print FH "\n";
close(FH);
}

[download]

Now the problem is this code goes well if there is a family name after prot_fam then parent entry(2 times) in the HTML source page. However, when a family is not defined the structure of the source of html webpage is actually different; after the line with 'prot_fam' there is written "No family membership assigned", but there is no 'entry parent' in the following lines. And when this perl script finds an entry in a list of codes where there is "No family membership assigned" written on webpage, it stops working forward. What I want is that this perl script should move forward and it should skip the entries with "No family membership assigned" information. I am new to perl. Please help me solve this problem. I will be grateful.

In reply to Reading particular information from Html page and skipping the page that doesn't contain that information by rmgzsm9

Title:
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