How send user to other screen using user exit in Sales order

Hi,

I have requirement where we want to show a pop up message at the time of saving sales order.

If user click on Yes button then I need to navigate user to Header->Partners tab

If user clicks on No button then normal saving process should happen.

I know that I can put this in MV45AFZZ->Save_prepare.

My question is how can I navigate user to Partners screen?

Anybody has done any such thing, please advise.

Thanks in advance.