AssertionError: The model ir.actions.url does not exist !

I'm going to add menu item when click on that which is navigate user to google.com. i tried with code in forums but its not worked and gives above error. please advice me to implement this issue & tell me if there another way to do thisGoogle URLhttp://www.google.com (if we need to open web page within exist openerp page & inside a frame, then how above code need to change ? )