Custom Ribbon Action

Hi All,

I followed following links to create a custom ribbon action for a specific content type. The action/button appears correctly when i access the default list/library view. But if I place the list view on a webpart page, the action/button does not show-up.

What "CommandUIDefinition Location="?"" do i need to set so that that action appears on any web part or wiki page containing the list view.

http://jakejacobsen.net/2010/06/17/sharepoint-ribbon-customization-for-content-types/

http://www.sharepointnutsandbolts.com/2010/01/customizing-ribbon-part-1-creating-tabs.html

Please help!!!