--- image_captcha.module	2011-02-07 01:45:12.000000000 +0500
+++ image_captcha_new.module	2011-04-23 18:16:13.015625000 +0600
@@ -60,6 +60,12 @@ function image_captcha_menu() {
     'access callback' => TRUE,
     'type' => MENU_CALLBACK,
   );
+  // callback for re-freshing image
+  $items['image_captcha_refresh'] = array(
+    'page callback' => 'image_captcha_captcha_refresh',
+    'access callback' => TRUE,
+    'type' => MENU_CALLBACK
+  );
   return $items;
 }
 
@@ -220,9 +226,12 @@ function image_captcha_captcha($op, $cap
         // client side caching: subsequent images of the same CAPTCHA session
         // have the same URL, but should display a different code).
         $img_src = check_url(url("image_captcha/$captcha_sid/". time()));
+        $result['image_url'] = $img_src;
+        
         $result['form']['captcha_image'] = array(
           '#type' => 'markup',
-          '#value' => '<img src="'. $img_src .'" alt="'. t('Image CAPTCHA') .'" title="'. t('Image CAPTCHA') .'" />',
+          '#value' => '<img src="'. $img_src .'" id="image-captcha-image" alt="'. t('Image CAPTCHA') .'" title="'. t('Image CAPTCHA') .'" />',
+          '#suffix' => '<a href="javascript:void(0)" onclick= "image_captcha_change_image();return false;" title="'.t('Refresh code').'">'.t('Refresh code').'</a>',
           '#weight' => -2,
         );
         $result['form']['captcha_response'] = array(
@@ -244,10 +253,40 @@ function image_captcha_captcha($op, $cap
             break;
         }
 
-
+        drupal_add_js(array(
+          'image_captcha' => array(
+            'ajaxUrl' => url('image_captcha_refresh/'.$captcha_sid.'/', array('absolute'=>true)),
+          ),
+        ), 'setting');
+        drupal_add_js('
+        function image_captcha_change_image() {
+          $.get(
+            Drupal.settings.image_captcha.ajaxUrl
+            + $("input[@name=\'form_id\']").val()
+            + "/"
+            + $("input[@name=\'captcha_token\']").val(),
+            function(response) {
+              $("#image-captcha-image").attr("src",response);
+              $("#edit-captcha-response").val("");
+            }
+          );
+          return false;
+        }
+        ', 'inline');
         return $result;
       }
       break;
 
   }
 }
+
+/**
+ * menu callback function that refresh the CAPTCHA image
+ */
+function image_captcha_captcha_refresh($captcha_sid, $form_id, $captcha_token) {
+  $result = image_captcha_captcha('generate', 'Image', $captcha_sid);
+  db_query("UPDATE {captcha_sessions} SET solution='%s' WHERE %d=csid AND '%s'=token", $result['solution'], $captcha_sid, $captcha_token);
+  
+  echo $result['image_url'];
+  exit;
+}