Fixing the issue4860. Escaping the embedded '"' in the js_output method of Morsel class.
diff --git a/Lib/http/cookies.py b/Lib/http/cookies.py
index 03d1627..695161a 100644
--- a/Lib/http/cookies.py
+++ b/Lib/http/cookies.py
@@ -392,7 +392,7 @@
         document.cookie = \"%s\";
         // end hiding -->
         </script>
-        """ % ( self.OutputString(attrs), )
+        """ % ( self.OutputString(attrs).replace('"',r'\"'))
     # end js_output()
 
     def OutputString(self, attrs=None):
diff --git a/Lib/test/test_http_cookies.py b/Lib/test/test_http_cookies.py
index 01017e1..158dd63 100644
--- a/Lib/test/test_http_cookies.py
+++ b/Lib/test/test_http_cookies.py
@@ -50,17 +50,17 @@
 
         self.assertEqual(C.output(['path']),
             'Set-Cookie: Customer="WILE_E_COYOTE"; Path=/acme')
-        self.assertEqual(C.js_output(), """
+        self.assertEqual(C.js_output(), r"""
         <script type="text/javascript">
         <!-- begin hiding
-        document.cookie = "Customer="WILE_E_COYOTE"; Path=/acme; Version=1";
+        document.cookie = "Customer=\"WILE_E_COYOTE\"; Path=/acme; Version=1";
         // end hiding -->
         </script>
         """)
-        self.assertEqual(C.js_output(['path']), """
+        self.assertEqual(C.js_output(['path']), r"""
         <script type="text/javascript">
         <!-- begin hiding
-        document.cookie = "Customer="WILE_E_COYOTE"; Path=/acme";
+        document.cookie = "Customer=\"WILE_E_COYOTE\"; Path=/acme";
         // end hiding -->
         </script>
         """)