This is a fairly advanced exercise. This is a friend selector like you would see on facebook
Show names here. id=show_names_here
Show the names of the people you have selected (comma separated) in the area above This link has id=show_names
Alert the 'ids' of the people, comma separated. (they are stored in a hidden input within the .friend div) This link has id=alert_ids
Step 1 - when clicking on the divs, which have class .friend, add the class 'selected'. If you click it again, remove the 'selected' class. I've done some css. Hint, you are toggling the class!
Step 2: do the
Additional: show the people in the list as you select them.
Additional: create a JSON object of the friend IDs and pass it to another page via AJAX. This is how you would most likely use a friend selector in real life.