diff --git a/esi.admin.inc b/esi.admin.inc
new file mode 100644
index 0000000..b2b3bd3
--- /dev/null
+++ b/esi.admin.inc
@@ -0,0 +1,29 @@
+<?php
+
+/**
+ * Admin settings form
+ */
+function esi_admin_settings() {
+  $form = array();
+
+  $form['esi_block_default_enabled'] = array(
+    '#title' => 'Default block setting',
+    '#type' => 'radios',
+    '#options' => array(0 => 'Off', 1 => 'ESI', 2 => 'AJAX'),
+    '#default_value' => variable_get('esi_block_default_enabled', ESI__BLOCK_CONFIG_DEFAULT__IS_ENABLED),
+  );
+  $form['esi_seed_rotation_interval'] = array(
+    '#title' => 'Default seed key rotation interval',
+    '#type' => 'textfield',
+    '#default_value' => variable_get('esi_seed_rotation_interval', ESI__DEFAULT_SEED_KEY_ROTATION_INTERVAL),
+  );
+  $form['esi_block_default_ttl'] = array(
+    '#title' => 'Default block TTL',
+    '#type' => 'textfield',
+    '#default_value' => variable_get('esi_block_default_ttl', ESI__BLOCK_CONFIG_DEFAULT__TTL),
+    '#description' => t('Time-to-live on the proxy-cache'),
+  );
+
+  return system_settings_form($form);
+}
+
diff --git a/esi.inc b/esi.inc
index 7d40e9b..d6ed242 100644
--- a/esi.inc
+++ b/esi.inc
@@ -91,8 +91,8 @@ function _esi__block_settings($module, $delta, $config = NULL) {
   }
   else {
     $config = new stdClass;
-    $config->enabled = ESI__BLOCK_CONFIG_DEFAULT__IS_ENABLED;
-    $config->ttl     = ESI__BLOCK_CONFIG_DEFAULT__TTL;
+    $config->enabled = variable_get('esi_block_default_enabled', ESI__BLOCK_CONFIG_DEFAULT__IS_ENABLED);
+    $config->ttl     = variable_get('esi_block_default_ttl', ESI__BLOCK_CONFIG_DEFAULT__TTL);
   }
 
   return $config;
diff --git a/esi.js b/esi.js
new file mode 100644
index 0000000..ccba67e
--- /dev/null
+++ b/esi.js
@@ -0,0 +1,11 @@
+Drupal.behaviors.esi = function(context) {
+  $(".esi-ajax:not(.esi-ajax-processed)").each(function() {
+    $(this).addClass('esi-ajax-processed');
+    var css_id = $(this).attr('id');
+    var src = Drupal.settings.esi[css_id];
+    $.get(src, function(data) {
+      $('#' + css_id).replaceWith(data);
+      Drupal.attachBehaviors(data);
+    });
+  });
+}
diff --git a/esi.module b/esi.module
index 7d381cc..13db807 100755
--- a/esi.module
+++ b/esi.module
@@ -14,7 +14,9 @@ define('ESI__BLOCK_CONFIG_DEFAULT__IS_ENABLED', TRUE);
 // Default TTL for blocks: 5 minutes
 define('ESI__BLOCK_CONFIG_DEFAULT__TTL', 300);
 
-
+// ESI block setting constants
+define('ESI__BLOCK_CONFIG_ESI', 1);
+define('ESI__BLOCK_CONFIG_AJAX', 2);
 
 /**
  * Implementation of hook_theme().
@@ -45,19 +47,35 @@ function esi_theme_registry_alter(&$theme_registry) {
 
 
 /**
+ * Implementation of hook_init().
+ */
+function esi_init() {
+  drupal_add_js(drupal_get_path('module', 'esi') . '/esi.js');
+}
+
+/**
  * Implementation of hook_menu().
  *   Define a menu-handler.
  */
 function esi_menu() {
-  return array(
-    'esi/block/%' => array(
-      'title' => 'ESI handler',
-      'page callback' => 'esi__block_handler',
-      'page arguments' => array(2),
-      'access callback' => TRUE,
-      'type' => MENU_CALLBACK
-    )
+  $items = array();
+  $items['esi/block/%'] = array(
+    'title' => 'ESI handler',
+    'page callback' => 'esi__block_handler',
+    'page arguments' => array(2),
+    'access callback' => TRUE,
+    'type' => MENU_CALLBACK
+  );
+  $items['admin/settings/esi'] = array(
+    'title' => 'ESI default settings',
+    'description' => 'ESI default settings',
+    'page callback' => 'drupal_get_form',
+    'page arguments' => array('esi_admin_settings'),
+    'access arguments' => array('administer site configuration'),
+    'file' => 'esi.admin.inc',
+    'type' => MENU_CALLBACK,
   );
+  return $items;
 }
 
 
@@ -139,8 +157,9 @@ function esi_form_block_admin_configure_alter(&$form, $form_state) {
   );
 
   $element['esi_config']['enabled'] = array(
-    '#type' => 'checkbox',
+    '#type' => 'radios',
     '#title' => t('Enable ESI'),
+    '#options' => array(0 => 'Off', 1 => 'ESI', 2 => 'AJAX'),
     '#default_value' => $config->enabled,
   );
 
diff --git a/esi.theme.inc b/esi.theme.inc
index 60a1870..1365447 100644
--- a/esi.theme.inc
+++ b/esi.theme.inc
@@ -17,7 +17,7 @@ function esi__theme_blocks($region) {
       // if ESI's enabled on the block, add an ESI tag instead of block content.
       $esi_config = _esi__block_settings($block->module, $block->delta);
       $output .= $esi_config->enabled
-        ? theme('esi_tag', $block)
+        ? theme('esi_tag', $block, $esi_config->enabled)
         : theme('block', $block);
     }
   }
@@ -32,7 +32,7 @@ function esi__theme_blocks($region) {
 /**
  * Create the ESI-tag for a particular block.
  */
-function theme_esi_tag($block) {
+function theme_esi_tag($block, $setting) {
   global $theme_key, $base_url;
 
   $bid = "{$theme_key}:{$block->region}:{$block->module}:{$block->delta}";
@@ -51,6 +51,17 @@ function theme_esi_tag($block) {
     $src .= '/CACHE=' . ($block->cache & BLOCK_CACHE_PER_USER ? 'USER' : 'ROLE');
   }
 
-  $output = '<esi:include src="' . $src . '" />';
+  switch ($setting) {
+    case ESI__BLOCK_CONFIG_AJAX:
+      $css_id = "{$theme_key}-{$block->region}-{$block->module}-{$block->delta}";
+      $output = '<div id="' . $css_id. '" class="esi-ajax"></div>';
+      drupal_add_js(array('esi' => array(
+        $css_id => $src,
+      )), 'setting');
+      break;
+    case ESI__BLOCK_CONFIG_ESI:
+      $output = '<esi:include src="' . $src . '" />';
+      break;
+  }
   return $output;
 }