payment block rewrite not working

Question

I want to rewrite Mage/Payment/Block/Form/Container.php with another file inside my module.

In my module's config file, I have:

<global>
  <blocks>
     <payment_form>
         <rewrite>
            <container>Mynamespace_Module_Block_Form_Container</container>
         </rewrite>
     </payment_form>
  </blocks>
</global>

I've also tried this:

<global>
 <blocks>
   <payment>
     <rewrite>
        <form_container>Mynamespace_Module_Block_Form_Container</form_container>
   </rewrite>
  </payment>
 </blocks>
</global>

I have then, in my Module, Mynamespace/Module/Block/Form/Container.php

<?php

class Mynamespace_Module_Block_Form_Container extends Mage_Core_Block_Template
{
  protected function _prepareLayout()
  {
    echo "hello world";
  }
}

none of the above solutions are working. it's still picking up the old block inside Mage/Payment/Block/Form/Container.php

Could it be because my module lives in local code pool??

Answer 1

Change this: <container_form>Mynamespace_Module_Block_Form_Container</container_form>

to this: <form_container>Mynamespace_Module_Block_Form_Container</form_container>