$(document).ready (function () {
  $('#submit_btn').click(function() {

    $.get('server.php', {
        process: 'login',
        user: $('#user_name').val(),
        password: Sha1.hash($('#password').val())
    });
  });
});

function successful_login() {
  window.location = 'composid/pleasewait.html';
}

function unsuccessful_login() {
  alert('Failed to log in, please try again');
}