title: CodeIgniter using same login for different subdomain
body: <p>I am using CodeIgniter 2.1.4 for one of my application.</p>
  
  <p>I am sharing all files and folder with different subdomain, but using different database.</p>
  
  <p>Now in this I am getting problem if I login with any one domain than for other subdomain it directly get login.</p>
  
  <p>Like if I login to www.example.com/sub1
  than when I go to www.example.com/sub2 it doesn't ask for login it directly use the login of sub1.</p>
  
  <p>How can I prevent this.</p>