diff --git a/includes/ajax.inc b/includes/ajax.inc
index 50e8e28..6f16ef4 100644
--- a/includes/ajax.inc
+++ b/includes/ajax.inc
@@ -796,6 +796,7 @@ function ajax_pre_render_element($element) {
       'type' => 'setting',
       'data' => array(
         'ajax' => array($element['#id'] => $settings),
+        'ajaxErrorDisplay' => variable_get('ajax_error_level', AJAX_ERROR_REPORTING_ALERT),
         'urlIsAjaxTrusted' => array(
           $settings['url'] => TRUE,
         ),
diff --git a/includes/bootstrap.inc b/includes/bootstrap.inc
index b66ae17..59c2b45 100644
--- a/includes/bootstrap.inc
+++ b/includes/bootstrap.inc
@@ -41,6 +41,16 @@ define('ERROR_REPORTING_DISPLAY_SOME', 1);
 define('ERROR_REPORTING_DISPLAY_ALL', 2);
 
 /**
+ * Ajax error reporting level: display errors is alert window.
+ */
+define('AJAX_ERROR_REPORTING_ALERT', 0);
+
+/**
+ * Ajax error reporting level: display errors in console.
+ */
+define('AJAX_ERROR_REPORTING_CONSOLE', 1);
+
+/**
  * Indicates that the item should never be removed unless explicitly selected.
  *
  * The item may be removed using cache_clear_all() with a cache ID.
diff --git a/misc/ajax.js b/misc/ajax.js
index bb4a6e1..fbe3383 100644
--- a/misc/ajax.js
+++ b/misc/ajax.js
@@ -230,16 +230,16 @@ Drupal.ajax = function (base, element, element_settings) {
  * will test to see if the key press is valid to trigger this event and
  * if it is, trigger it for us and prevent other keypresses from triggering.
  * In this case we're handling RETURN and SPACEBAR keypresses (event codes 13
- * and 32. RETURN is often used to submit a form when in a textfield, and 
- * SPACE is often used to activate an element without submitting. 
+ * and 32. RETURN is often used to submit a form when in a textfield, and
+ * SPACE is often used to activate an element without submitting.
  */
 Drupal.ajax.prototype.keypressResponse = function (element, event) {
   // Create a synonym for this to reduce code confusion.
   var ajax = this;
 
   // Detect enter key and space bar and allow the standard response for them,
-  // except for form elements of type 'text' and 'textarea', where the 
-  // spacebar activation causes inappropriate activation if #ajax['keypress'] is 
+  // except for form elements of type 'text' and 'textarea', where the
+  // spacebar activation causes inappropriate activation if #ajax['keypress'] is
   // TRUE. On a text-type widget a space should always be a space.
   if (event.which == 13 || (event.which == 32 && element.type != 'text' && element.type != 'textarea')) {
     $(ajax.element_settings.element).trigger(ajax.element_settings.event);
@@ -476,7 +476,15 @@ Drupal.ajax.prototype.getEffect = function (response) {
  * Handler for the form redirection error.
  */
 Drupal.ajax.prototype.error = function (xmlhttprequest, uri, customMessage) {
-  alert(Drupal.ajaxError(xmlhttprequest, uri, customMessage));
+  if (Drupal.settings.ajaxErrorDisplay === '1') {
+    if (typeof(window.console) !== 'undefined') {
+      window.console.log(Drupal.ajaxError(xmlhttprequest, uri, customMessage));
+    }
+  }
+  else {
+    alert(Drupal.ajaxError(xmlhttprequest, uri, customMessage));
+  }
+
   // Remove the progress element.
   if (this.progress.element) {
     $(this.progress.element).remove();
diff --git a/misc/autocomplete.js b/misc/autocomplete.js
index d71441b..eb27df3 100644
--- a/misc/autocomplete.js
+++ b/misc/autocomplete.js
@@ -310,7 +310,14 @@ Drupal.ACDB.prototype.search = function (searchString) {
         }
       },
       error: function (xmlhttp) {
-        alert(Drupal.ajaxError(xmlhttp, db.uri));
+        if (Drupal.settings.ajaxErrorDisplay === '1') {
+          if (typeof(window.console) !== 'undefined') {
+            window.console.log(Drupal.ajaxError(xmlhttp, db.uri));
+          }
+        }
+        else {
+          alert(Drupal.ajaxError(xmlhttp, db.uri));
+        }
       }
     });
   }, this.delay);
diff --git a/modules/system/system.admin.inc b/modules/system/system.admin.inc
index 8ef7d7c..cfd87c7 100644
--- a/modules/system/system.admin.inc
+++ b/modules/system/system.admin.inc
@@ -1676,6 +1676,16 @@ function system_logging_settings() {
     '#description' => t('It is recommended that sites running on production environments do not display any errors.'),
   );
 
+  $form['ajax_error_level'] = array(
+    '#type' => 'radios',
+    '#title' => t('Ajax errors to display'),
+    '#default_value' => variable_get('ajax_error_level', AJAX_ERROR_REPORTING_ALERT),
+    '#options' => array(
+      AJAX_ERROR_REPORTING_ALERT => t('Show in alert window'),
+      AJAX_ERROR_REPORTING_CONSOLE => t('Show in console'),
+    ),
+  );
+
   return system_settings_form($form);
 }