Menu with link in the same page

Hi! I would do one page site with a menu with links in the same page... But i don't know how to do

link to anchor , so menu item link can be "#anchor1" (use external URL menu item type) and target place in content <span name="anchor1"> place on page 1</span>

Sorry but where i have to write <span name="anchor1">place on page 1</span>?

Anywhere in content. So if you want to position on some article you would put that as first tag in article content