title: using CAS with with custom login page
body: <p>I've implemented jasig-CAS in my application, but now I'd like to know more.
  Is it possible to do my own login page and then it would automatically(in background) authenticate the user in CAS.
  so the steps are next:</p>
  
  <ol>
  <li>user goes to the login page </li>
  <li>user enters his credentials</li>
  <li>if authentication succeeded, user's credentials are sent to CAS, thus CAS authenticates user in its system and gives a ticket(user shouldn't see any CAS pages)</li>
  <li>user accesses protected pages</li>
  </ol>
  
  <p>thanks.</p>