To delete a page from a Web Form, select the "Questions" option from the Web Form listing. For any existing pages, there will be a "Delete" link beside the page name. Clicking this link will delete the page from the form.

Note: Deleting a page does NOT delete the questions associated with the page. Questions will be moved to the previous page and must be deleted separately (unless the page being deleted is the first page in the Web Form, in which case the questions will be moved to the next page, which will become the new first page after the current first page is deleted).