create a submenu under Customers Menu in magento

Question

I know how to create a sub-menu under catalog main navigation menu in config.xml which is:

<menu>
    <catalog>
    <children>
        <testimonials>
                <title>Manage Testimonials</title>
                <sort_order>1</sort_order>
                <action>adminhtml/adminhtml_testimonials</action>
        </testimonials>
    </children>
</catalog>
</menu>

but how do I create a sub-menu under Customers Menu? I tried:

<menu>
    <customers>
    <children>
        <testimonials>
                <title>Manage Testimonials</title>
                <sort_order>1</sort_order>
                <action>adminhtml/adminhtml_testimonials</action>
        </testimonials>
    </children>
</customers>
</menu>

but it doesn't work. Any suggestion would be appreciated.

Answer 1

Assuming that this is not a permission issue and you have clear cache and re-login.

In config.xml

<?xml version="1.0"?>
<config>  
  ....
  <adminhtml>  <---
    <menu>
      <customer>
        <children>
          <testimonials>
            <title>Manage Testimonials</title>
            <sort_order>0</sort_order>
            <action>adminhtml/adminhtml_testimonials</action>
          </testimonials>
        </children>
      </customer>
    </menu>
  </adminhtml>  <---      
 ....

or

In adminhtml.xml

<?xml version="1.0"?>
<config> 
  ... 
  <menu>
      <customer>
        <children>
          <testimonials>
            <title>Manage Testimonials</title>
            <sort_order>0</sort_order>
            <action>adminhtml/adminhtml_testimonials</action>
          </testimonials>
        </children>
      </customer>
    </menu>
 ...