submitting form value using POST method to a secure site

[Pritesh Sheth]

Hello:

I'm trying to submit a form with value "abc123?LIST, UID=efg, 
PWD=hijk~". This works fine when I submit via a browser. But when I try 
to send the same via the following code -
   use LWP::UserAgent;
   $ua = LWP::UserAgent->new;
   my $req=HTTP::Request->new(POST=>"https://xyz.com/servlet/post2jms";);
   $req->content_type('application/x-www-form-urlencoded');
   $req->content('abc123?LIST, UID=efg, PWD=hijk~');
   $res = $ua->request($req,"some-result.txt"    );
   if ($res->is_success) {
    print "ok\n";
    print $res->as_string, "\n";
 }
 else {
    print $res->as_string, "\n";
    print $res->status_line, "\n";
 } 

- I get a "HTTP/1.1 500 (Internal Server Error) Server Error"

Can anyone help please?

-Pritesh