$(document).on('click','#page_login_submit',function(){
var name = $('#page_login_name').val();
  if (!name) { alert('Please enter your user name.'); return false; }
  var pass = $('#page_login_pass').val();
  if (!pass) { alert('Please enter your password.'); return false; }
try{
    $.ajax({
          url: "http://your_url/endpoint/user/login.json",
          type: 'post',
          data: 'username=' + encodeURIComponent(name) + '&password=' + encodeURIComponent(pass),
          dataType: 'json',
          error: function(jqXHR, textStatus, errorThrown) {
            alert('page_login_submit - failed to login');
            alert(JSON.stringify(jqXHR));
            alert(JSON.stringify(textStatus));
            alert(JSON.stringify(errorThrown));
          },
          success: function (data) {
          var drupal_user = data.user;
          alert ('welcome ' + drupal_user.name);
          $.mobile.changePage("index.html", "slideup");
          }});


      // END: drupal services user login
      return false;
  }
catch(error) { alert("login - " + error)};
});