my $uri = 'http://sp/Survey.aspx';
my $ua = new LWP::UserAgent;

my $boundary = '------WebKitFormBoundary0x';
my @rand = ('a'..'z', 'A'..'Z');    
for (0..14) {$boundary .= $rand[rand(@rand)];}

my $request = HTTP::Request->new('POST', $uri);
$request->header('Content-Type' => 'multipart/form-data; boundary='.$boundary);

$request->protocol('HTTP/1.0');

my $field1 = HTTP::Message->new([ 'Content-Disposition' => 'form-data; name="my_id"', ]);    	
$field->add_content_utf8('TEST5');
$request->add_part($field);
...
...
my $response = $ua->request($request);