[Drupal] Submit and redirect back to the modify page

First you have to create a new module called "my_submit", and in the my_submit.module, insert the code as below: 

<?php
// $Id:

/********************************   READ ME     **********************
 *
 * 
    No addons required. Drop the entire submit again folder in your modules directory,
    usually sites/all/modules on your Drupal filesystem, activate it on the modules
    page, and turn it on for each content type it should be attached to at

      Administer -> Content management -> Content types -> (edit each content type)
 *
 *
 *************************Create by DavidHHuan*******************/

/**
 * @file
 * Add a new button to node creation forms that
 * allows the content author to return to the node
 * creation form after saving new content instead
 * of going to the view page of the new content.
 */

/**
 * Implementation of hook_form_alter().
 */
function my_submit_form_alter(&$form, $form_state, $form_id) {
  if (strpos($form_id, '_node_form') && !isset($form['nid']['#value'])) {
    if (variable_get('my_submit_'. $form['type']['#value'], FALSE)) {
      $form['buttons']['my_submit'] = array(
        '#type' => 'submit',
        '#value' => t('Save and review'),
        '#weight' => 41,
        '#submit' => array('node_form_submit', 'my_submit_node_form_submit'),
      );
    }
  }
}

function my_submit_node_form_submit($form, &$form_state) {
  //Go back to the content edit page which is created just now.
  $form_state['redirect'] .= '/edit';
}

/**
 * Alter content type settings to add "Submit Again?" checkbox
 */
function my_submit_form_node_type_form_alter(&$form, &$form_state) {
  if (isset($form['identity']['type'])) {
    $form['submission']['my_submit'] = array(
      '#type' => 'checkbox',
      '#title' => t('Submit and review?'),
      '#default_value' => variable_get('my_submit_'. $form['#node_type']->type, FALSE),
      '#description' => t('Enable this checkbox if you want to provide a "Save and review" button for your users.')
    );
  }
}

I have added readMe in the code comment.