I have a custom object BillingInformation which has a lookup to Account. It appears as a related list on the account page. I also have a button "New Billing Information" on this related list, which opens a visualforce page I have written for creating new BillingInformation objects. So, a person on an Account page can click "New Billing Information" associated with that account.
However, when the New Billing Information page opens, the "Account" field is blank. I would like the Account field to be pre-filled with the Account I just navigated from. How can I accomplish this using VisualForce and Apex?
I'm using a custom controller - Not a controller extension.