dashboard.js

$('#page_dashboard').on('pageshow',function(){
try{
$.ajax({
  url:"http://your_url/services/session/token",
  dataType:"text",
  error:function (jqXHR, textStatus, errorThrown) {
    alert(jqXHR);
    alert(textStatus);
  },
  success: function (token) {
    // Call system connect with session token.
    $.ajax({
      url: 'http://your_url/drupal/endpoint/system/connect.json',
      type: "post",
      dataType: "json",
      beforeSend: function (request) {
        request.setRequestHeader("X-CSRF-Token", token);
      },
      error: function (jqXHR, textStatus, errorThrown) {
      alert(jqXHR);
      alert(textStatus);
      //  alert(errorThrown);
      },
      success: function (data) {
       var drupal_user = data.user;
       if (drupal_user.uid == 0) { // user is not logged in, show the login button, hide the logout button
                 $('#button_login').show();
                 $('#button_logout').hide();
               }
               else { // user is logged in, hide the login button, show the logout button
                 $('#button_login').hide();
                 $('#button_logout').show();
               }
      }
    });
  }
});
}
catch(error) { alert("page_dashboard - " + error)};
});

$(document).on("click",'#button_logout',function(){
try {
    $.ajax({
  url:"http://your_url/services/session/token",
  type:"get",
  dataType:"text",
  error:function (jqXHR, textStatus, errorThrown) {
   alert(jqXHR);
   alert(textStatus);
   // alert(errorThrown);
  },
  success: function (token) {
    // Call system connect with session token.
    $.ajax({

     url: "http://your_url/endpoint/user/logout.json",
     type: 'post',
     dataType: 'json',
     beforeSend: function (request) {
        request.setRequestHeader("X-CSRF-Token", token);
      },
     error: function (jqXHR, textStatus, errorThrown) {
       alert('button_logout - failed to logout');
       alert(JSON.stringify(jqXHR));
       alert(JSON.stringify(textStatus));
       alert(JSON.stringify(errorThrown));
     },
     success: function (data) {
       alert("You have been logged out.");
       $.mobile.changePage("index.html",{reloadPage:true},{allowSamePageTranstion:true},{transition:'none'});
     }
 });
  }
});

}
catch (error) { alert("button_logout - " + error); }
});