For a customer’s site I needed to create a custom display form (DispForm.aspx) so that I can change the action of the Close button on the Display Page to return user to home page instead of the list page, and I can hide the bread crumbs.
This is the reference I used: http://office.microsoft.com/en-us/sharepointdesigner/HA101191111033.aspx
Don’t forget to open site in SP Designer, right-click on list in question, select ‘Properties’, select ‘Supporting Files’, and browse to new DispForm.aspx file.
For me, I renamed the original DispForm.aspx to DispForm_Default.apx made a copy of it named DispForm.aspx, but Sharepoint list still points to renamed file until you go select new file in properties area.