I guess this is where I am confused, as to what do I need to specify in the URL so I can force the page to run using my data. I thought it was enough to put:

my $url = 'http://www.csbio.sjtu.edu.cn/bioinf/MemBrain/';
my $mech = WWW::Mechanize->new (timeout=>1000);
$mech->post($url);
#$mech->get($url);
[download]

but it fails to run with the error: Error POSTing http://www.csbio.sjtu.edu.cn/cgi-bin/MEMBRAIN.cgi: Internal Server Error or Error GETing http://www.csbio.sjtu.edu.cn/cgi-bin/MEMBRAIN.cgi: Internal Server Error
I even tried: my $url=http://www.csbio.sjtu.edu.cn/cgi-bin/MEMBRAIN.cgi, still error...