function wp_egrid_ajax_set_default_photo_callback()
{
    $photo_id = $_REQUEST['photo_id'];
    $project_id = $_REQUEST['project_id'];
    //update record in database
    require 'model/project_model.php';
    $projectModel = new ProjectModel();
    $projectModel->set_default_image_thumbnail($project_id, $photo_id);
    die;
}