Adding custom button in Edit form

Hi,

How to add custom buttons in Edit form in a custom list.

I am trying to add two buttons - Approve and Reject.

On click of the button , I have a dropdown box which needs to be updated with value as Yes and list item saved, when Approve is clicked and the page closed. If the reject button is clicked, the dropdown should be set as No and list items saved , and the page closed.

How to achieve this using javascript / jquery ?

Thanks