diff --git a/browser/components/nsBrowserGlue.js b/browser/components/nsBrowserGlue.js
index 46ca331f1..2e1338c0f 100644
--- a/browser/components/nsBrowserGlue.js
+++ b/browser/components/nsBrowserGlue.js
@@ -978,6 +978,11 @@ BrowserGlue.prototype = {
             win.skipNextCanClose = true;
             win.close();
           }
+        },
+        runScriptInTabAtIndexInWindow : function(index, window_index,
+            script) {
+          throw Components.Exception("NYI", Cr.NS_ERROR_FAILURE);
+          return null;
         }
       }
 
diff --git a/toolkit/components/applescript/public/nsIApplescriptService.idl b/toolkit/components/applescript/public/nsIApplescriptService.idl
index 45b91f90d..a09eddb09 100644
--- a/toolkit/components/applescript/public/nsIApplescriptService.idl
+++ b/toolkit/components/applescript/public/nsIApplescriptService.idl
@@ -142,6 +142,20 @@ interface nsIApplescriptService : nsISupports
      * @param index The window's index.
      */
     void setWindowIsFullScreen(in unsigned long index, in bool fullscreen);
+
+   /**
+    * Returns the result of a JavaScript operation done within this tab's doc.
+    *
+    * @param index The tab's index.
+    * @param window_index The window's index.
+    * @param script The script to execute.
+    * @param result The result, as a string.
+    * @return true if the script execution ran without errors
+    */
+   boolean runScriptInTabAtIndexInWindow(in unsigned long index,
+                                         in unsigned long window_index,
+                                         in AUTF8String script,
+                                         out AUTF8String result);
 };
 
 [scriptable, uuid(45f087af-9c24-4fc6-9325-359382196a4e)]
@@ -234,4 +248,18 @@ interface nsIApplescriptTabCallback : nsISupports
     * @param window_index The window's index.
     */
    void reloadTabAtIndexInWindow(in unsigned long index, in unsigned long window_index);
+
+   /**
+    * Returns the result of a JavaScript operation done within this tab's doc.
+    *
+    * @param index The tab's index.
+    * @param window_index The window's index.
+    * @param script The script to execute.
+    * @param result The result, as a string.
+    * @return true if the script execution ran without errors
+    */
+   bool runScriptInTabAtIndexInWindow(in unsigned long index,
+                                      in unsigned long window_index,
+                                      in AUTF8String script,
+                                      out AUTF8String result);
 };
diff --git a/toolkit/components/applescript/src/nsApplescriptService.cpp b/toolkit/components/applescript/src/nsApplescriptService.cpp
index bc14607b0..5bddfcc39 100644
--- a/toolkit/components/applescript/src/nsApplescriptService.cpp
+++ b/toolkit/components/applescript/src/nsApplescriptService.cpp
@@ -157,6 +157,22 @@ nsApplescriptService::ReloadTabAtIndexInWindow(uint32_t index, uint32_t window_i
   return NS_OK;
 }
 
+NS_IMETHODIMP
+nsApplescriptService::RunScriptInTabAtIndexInWindow(uint32_t index,
+                                                    uint32_t window_index,
+                                                    const nsACString& script,
+                                                    nsACString& result,
+                                                    bool* ok) {
+  if (tabCallback) {
+    return tabCallback->RunScriptInTabAtIndexInWindow(index, window_index, script, result, ok);
+  }
+  *ok = false;
+  result = NULL;
+  return NS_OK;
+}
+
+// ---------
+
 NS_IMETHODIMP
 nsApplescriptService::RegisterWindowCallback(nsIApplescriptWindowCallback *callback) {
   windowCallback = callback;