Defaulting the payment method

I have multiple payment methods and will be hiding them from customer view dependent on which cart page I am using.  I would like to set the default (checked) so that when the customer checks out their transaction will be automatically associated with the option I have designated. 

I tried overriding the template view and manually setting the selected value for the listitem as well as using javascript on the page and neither of these solutions work.

Thanks for any insight.

No one has had to do anything like this before???  Any other suggestions to get this working as I need it to?

Hey A,