Salesforce - where do I edit the fields included in the "Add Products" page?

I know how to edit the page layouts for th开发者_高级运维e opportunity products search page, when you search for products to add to an opportunity after choosing your price book. But what about the subsequent page, which displays the products I've selected and asks me to fill in quantity, price, etc. How can I add additional custom fields I've created to that page's layout?

The option to edit doesn't seem to appear in either Edit Page Layouts or Edit Search Layouts options under Opportunity Product Setup.

When you edit an Opportunity Product Page Layout, there is a link in the top named "Edit Multi-Line Layout". Go there to specify which fields you want on the "Add Products"/"Edit All" page.

Best Søren