use WWW::Mechanize();

while(<>)
{
if($_=~/^>(.*)/)
  {
    my $id=$1; 
    my  $seq=<>; chomp $seq; 

     print "$id\n";
     my $url = 'http://www.csbio.sjtu.edu.cn/bioinf/MemBrain/';  #what I see in the browser, as you said
     my $mech = WWW::Mechanize->new();
     $mech->get($url);

     $mech->submit_form
     (
    	 form_name => 'myform',
    	 fields      => 
    		{
        		#textarea name | value
        		S1 => ">$id\n$seq",

        		#Radio button one with value (parameter 1)
        		R4    =>  'TOPpre',

        		#Radio button one with value (parameter 2)
        		R2    =>  'SignalYES',

        		#Radio button one with value (parameter 3)
        		R3    =>  'Human',

        		#Fill in email (parameter 4)
        		email => 'myemail@gmail.com'
    		}
    	);
	}
}