I am following the exercise to Create Custom Controller Apex Class in Visualforce Basics -  I created the class and page ContactsListWithController - I added all the required code - I have a problem with the new action method - At the end the instructions say "Although the visual appearance remains the same, if you click the First Name and Last Name column headers now, they will change the sort order for the contacts list. Nice!" I do not get First Name or Last Name columns to click - I only get Last Name and when I click nothing happens - I am attaching screenshots of my code - I do not understand what I did wrong. Please check my code so can figure this out. Thank you