diff --git a/node_class.info b/node_class.info
index 1bb1b8b..3f301fd 100644
--- a/node_class.info
+++ b/node_class.info
@@ -1,4 +1,4 @@
 name = Node Class
 description = Allows assigning CSS classes to nodes.
 core = 7.x
-
+configure = admin/config/content/nodeclass
diff --git a/node_class.install b/node_class.install
index 75f17e3..1f35662 100644
--- a/node_class.install
+++ b/node_class.install
@@ -1,10 +1,10 @@
 <?php
+
 /**
  * @file
  * Install, update and uninstall functions for the block_class module.
  */
 
-
 /**
  * Implements hook_schema().
  */
@@ -14,16 +14,15 @@ function node_class_schema() {
       'nid' => array(
         'type' => 'varchar',
         'length' => '32',
-        'not null' => TRUE
+        'not null' => TRUE,
       ),
-
       'css_class' => array(
         'type' => 'varchar',
         'length' => '255',
         'not null' => TRUE,
         'default' => '',
         'description' => 'String containing the classes for the block.',
-      )
+      ),
     ),
     'primary key' => array('nid'),
   );
@@ -31,8 +30,19 @@ function node_class_schema() {
   return $schema;
 }
 
-
+/**
+ * Implements hook_install().
+ */
 function node_class_install() {
-  drupal_set_message('Node Class was installed. Check README.txt before using the module');
+  drupal_set_message(st('Node Class was installed. Check README.txt before using the module'), 'status');
 }
 
+/**
+ * Implements hook_uninstall().
+ */
+function node_class_uninstall() {
+  variable_del('node_class_location');
+  variable_del('node_class_widget');
+  variable_del('node_class_source');
+  variable_del('node_class_predefined_values');
+}
\ No newline at end of file
diff --git a/node_class.module b/node_class.module
index 21b79f7..2dd2bcc 100644
--- a/node_class.module
+++ b/node_class.module
@@ -1,51 +1,110 @@
 <?php
 
-/*
+/**
+ * @file
+ * node_class module.
+ */
+
+/**
+ * Implements hook_menu(). 
+ * Define form and the autocomplete callback.
+ */
+function node_class_menu() {
+  $items['admin/config/content/nodeclass'] = array(
+    'title' => 'Node Class',
+    'description' => 'Configure where the css classes should be displayed. Also allows settings for dropdown values.',
+    'page callback' => 'drupal_get_form',
+    'page arguments' => array('node_class_admin_form'),
+    'access arguments' => array('administer nodeclass settings'),
+    'type' => MENU_NORMAL_ITEM,
+  );
+  $items['nodeclass/autocomplete'] = array(
+    'title' => 'Node Class Autocomplete',
+    'page callback' => '_node_class_get_values_autocomplete',
+    'access arguments' => array('administer nodes'),
+    'type' => MENU_CALLBACK,
+  );
+
+  return $items;
+}
+
+/**
+ * Implements hook_permission().
+ */
+function node_class_permission() {
+  return array(
+    'administer nodeclass settings' => array(
+      'title' => t('Administer Node Class settings'),
+    ),
+  );
+}
+
+/**
  * Extends the node's classes with any user defined classes.
  */
 function node_class_preprocess_node(&$vars) {
-  $node = $vars['node'];
-  $classes = node_class($node);
+  $location = variable_get('node_class_location', 'node');
+  if ($location == 'node' || $location == 'both') {
+    $node = $vars['node'];
+    $classes = node_class($node);
+    $vars['classes_array'] = array_merge($vars['classes_array'], explode(' ', $classes));
+  }
+}
 
-  $vars['classes_array'] = array_merge($vars['classes_array'], explode(' ', $classes));
+/**
+ * Extends the body's classes with any user defined classes.
+ */
+function node_class_preprocess_html(&$vars) {
+  $location = variable_get('node_class_location', 'node');
+  if ($location == 'body' || $location == 'both') {
+    $node = menu_get_object();
+    $classes = node_class($node);
+    $vars['classes_array'] = array_merge($vars['classes_array'],
+      explode(' ', $classes));
+  }
 }
 
-/*
+/**
  * Accessor for css_class information
  */
 function node_class($node) {
   $attributes = node_class_attributes($node);
-
   return $attributes;
 }
 
-/*
+/**
  * Gets CSS class information for a given node.
  */
 function node_class_attributes($node) {
-  // dev note:
-  // Get css attribute information ONLY if node already existed.
-  // if we're here the $form[#node] object will have already been
-  // created but it won't have an nid because it hasn't been saved
-  if (!isset($node->nid)) {
-    return "";
+  if (isset($node->nid)) {
+    $query = db_select('node_class', 'n');
+    $query->fields('n', array('css_class'));
+    $query->condition('n.nid', $node->nid, '=');
+    $result = $query->execute()->fetchField();
   }
-
-  return db_query('SELECT css_class FROM {node_class} WHERE nid = :nid', array(':nid' => $node->nid))->fetchField();
+  return isset($result) ? $result : '';
 }
 
-/*
+/**
  * Implementation of hook_form_alter().
  */
 function node_class_form_alter(&$form, &$form_state, $form_id) {
-	// Check form type && if user_access is ok
-  if (isset($form['#node']) && ($form_id == $form['#node']->type .'_node_form') && user_access('administer nodes')) {
+  // Check form type && if user_access is ok
+  if (isset($form['#node']) && ($form_id == $form['#node']->type . '_node_form') &&
+    user_access('administer nodes')
+  ) {
+    // Add form elements in vertical tab to node settings.
     $form['node_class'] = array(
       '#type' => 'fieldset',
       '#title' => t('Node Class settings'),
+      '#description' => t('Assign CSS classes to the node.'),
       '#collapsible' => TRUE,
-      '#weight' => -1,
+      '#collapsed' => TRUE,
+      '#access' => user_access('administer nodes'),
+      '#weight' => 80,
       '#tree' => TRUE,
+      '#group' => 'additional_settings',
+      '#attributes' => array('class' => array('node-class-form')),
     );
 
     // Get css attribute information
@@ -66,43 +125,60 @@ function node_class_form_alter(&$form, &$form_state, $form_id) {
       '#description' => t('Separate classes with a space.'),
     );
 
-    // Add submit handler for node_class module
-    $form['#submit'][] = 'node_class_form_submit';
-	}
+    // Check the widget defined in the settings
+    $widget = variable_get('node_class_widget', 'textfield');
+    if ($widget == 'textfield') {
+      $form['node_class']['css_class']['#type'] = 'textfield';
+      $form['node_class']['css_class']['#description'] = t('Separate classes with a space.');
+    }
+    elseif ($widget == 'dropdown') {
+      $form['node_class']['css_class']['#type'] = 'select';
+      $form['node_class']['css_class']['#options'] = _node_class_get_values_dropdown($attributes);
+    }
+    elseif ($widget == 'autocomplete') {
+      $form['node_class']['css_class']['#type'] = 'textfield';
+      $form['node_class']['css_class']['#autocomplete_path'] = 'nodeclass/autocomplete';
+    }
+  }
 }
 
 /**
- * Form submission handler for node form.
+ * Implementation of hook_node_insert().
  */
- function node_class_form_submit($form, &$form_state) {
-   if ($form_state['values']['form_id'] == $form['#node']->type .'_node_form') {
-    if (isset($form_state['values']['node_class']['css_class']) && user_access('administer nodes')) {
-      $nid = $form_state['values']['nid'];
-      $class = check_plain($form_state['values']['node_class']['css_class']);
-
-      // update existing nodes that already have nid AND a class
-      if (isset($form_state['values']['node_class']['existing_css']) && !is_null($nid))  {
-        db_update('node_class')->fields(array('css_class' => $class))->condition('nid', $nid)->execute();
-       }
-
-      // update existing nodes that are getting classes for the first time
-      // quickest fix without a refactoring.
-      if (!isset($form_state['values']['node_class']['existing_css']) && !is_null($nid)
-       && !is_null($form_state['values']['node_class']['css_class']))  {
-      // technically this could replace the above, but merges are expensive.
-        db_merge('node_class')
-          ->key(array('nid' => $nid))
-          ->fields(array('css_class' => $class))
-          ->execute();
-       }
-     }
-   }
- }
+function node_class_node_insert($node) {
+  if (isset($node->node_class['css_class'])) {
+    $nid = $node->nid;
+    $class = check_plain($node->node_class['css_class']);
+    node_class_upsert($nid, $class);
+  }
+}
 
+/**
+ * Implementation of hook_node_update().
+ */
+function node_class_node_update($node) {
+  if (isset($node->node_class['css_class'])) {
+    $nid = $node->nid;
+    $class = check_plain($node->node_class['css_class']);
+    node_class_upsert($nid, $class);
+  }
+}
 
+/**
+ * Implementatios node_class_upsert().
+ */
+function node_class_upsert($nid, $class) {
+  $count = db_select('node_class', 'n')->fields('n', array('nid'))->condition('n.nid', $nid, '=')->execute()->rowCount();
+  if (!$count) {
+    $id = db_insert('node_class')->fields(array('nid' => $nid, 'css_class' => $class))->execute();
+  }
+  else {
+    db_update('node_class')->fields(array('css_class' => $class))->condition('nid', $nid)->execute();
+  }
+}
 
 /**
- * Implements hook_node_delete().
+ * Implementation of hook_node_delete().
  */
 function node_class_node_delete($node) {
   // Delete class information for the node
@@ -110,10 +186,117 @@ function node_class_node_delete($node) {
 }
 
 /**
- * Implements hook_node_insert().
+ * Creates the settings form.
  */
-function node_class_node_insert($node) {
-  if(isset($node->node_class['css_class']) && $node->node_class['css_class'] != '') {
-    $id = db_insert('node_class')->fields(array('nid' => $node->nid, 'css_class' => $node->node_class['css_class']))->execute();
+function node_class_admin_form() {
+  $form = array();
+  $form['node_class_location'] = array(
+    '#type' => 'radios',
+    '#title' => t('Node Class Location'),
+    '#default_value' => variable_get('node_class_location', 'node'),
+    '#options' => array('node' => t('Node (node.tpl.php)'), 'body' => t('Body (html.tpl.php)'), 'both' => t('Both')),
+    '#description' => t("Pick if the class will be displayed in node.tpl.php, html.tpl.php or both."),
+  );
+  $form['node_class_widget'] = array(
+    '#type' => 'select',
+    '#title' => t('Widget'),
+    '#default_value' => variable_get('node_class_widget', 'textfield'),
+    '#options' => array('textfield' => t('Textfield'), 'dropdown' => t('Dropdown'), 'autocomplete' => t('Autocomplete')),
+    '#description' => t("By default the widget is textfield. Use dropdown when you only use one value. Use autocomplete when you want autocomplete on multiple values."),
+  );
+  $form['node_class_source'] = array(
+    '#type' => 'select',
+    '#title' => t('Source of the dropdown/autocomplete'),
+    '#default_value' => variable_get('node_class_source', 'database'),
+    '#options' => array('database' => t('Database'), 'predefined' => t('Predefined set of values')),
+    '#description' => t("By choosing database, it'll search every distinct set of values. Predefined set of values allows the administrator to arbitrary define the classes available."),
+  );
+  $form['node_class_predefined_values'] = array(
+    '#type' => 'textarea',
+    '#title' => t('Predefined values'),
+    '#default_value' => variable_get('node_class_predefined_values', ''),
+    '#description' => t("Enter a list of classes separated by a space, comma, or line-break."),
+  );
+  $form['#attached']['js'][] = drupal_get_path('module', 'node_class') . '/node_class.js';
+
+  return system_settings_form($form);
+}
+
+/**
+ * Function to get all the values from the database/predefined and return them
+ * combined with the default value.
+ */
+function _node_class_get_values_dropdown($default) {
+  $result = array();
+  $result_keys = array();
+
+  // Check the source type.
+  $source = variable_get('node_class_source', 'database');
+  if ($source == 'database') {
+    $result = db_select('node_class', 'c')
+    ->fields('c', array('css_class'))
+    ->distinct()
+    ->execute()
+    ->fetchCol();
+  }
+  elseif ($source == 'predefined') {
+    // Gets the list of predefined values
+    $predefined = variable_get('node_class_predefined_values', '');
+    if (!empty($predefined)) {
+      $result = preg_split( "/[\s,]+/", $predefined);
+    }
+  }
+  if (!empty($default) && !in_array($default, $result)) {
+    array_unshift($result, $default);
   }
+  // Let's define a way to not specify any class.
+  $result_keys = $result;
+  array_unshift($result_keys, '');
+  array_unshift($result, t('- No Class -'));
+  return array_combine($result_keys, $result);
 }
+
+/**
+ * Function to get the values from the database/predefined filtered by a keyword
+ */
+function _node_class_get_values_autocomplete($keywords) {
+  $result = array();
+  $matches = array();
+  $keywords_exploded = preg_split( "/[\s,]+/", $keywords);
+  $last_keyword = trim(array_pop($keywords_exploded));
+
+  // Check the source type.
+  $source = variable_get('node_class_source', 'database');
+  if ($source == 'database') {
+    $result = db_select('node_class', 'c')
+    ->fields('c', array('css_class'))
+    ->condition('css_class', '%' . $last_keyword . '%', 'LIKE')
+    ->distinct()
+    ->range(0, 20)
+    ->execute()
+    ->fetchCol();
+  }
+  elseif ($source == 'predefined') {
+    // Gets the list of predefined values
+    $predefined = variable_get('node_class_predefined_values', '');
+    if (!empty($predefined)) {
+      $data = preg_split( "/[\s,]+/", $predefined);
+      $result = array_filter($data, function ($item) use ($last_keyword) {
+        if (stripos($item, $last_keyword) !== FALSE) {
+          return TRUE;
+        }
+        return FALSE;
+      });
+      $result = array_slice($result, 0, 20);
+    }
+  }
+
+  // Prefix the results with previous data to allow autocomplete to run for
+  // every word
+  $prefix = count($keywords_exploded) ? implode(' ', $keywords_exploded) . ' ' : '';
+  foreach ($result as $class) {
+    $matches[$prefix . $class] = check_plain($class);
+  }
+
+  return drupal_json_output($matches);
+}
\ No newline at end of file