How do I add a locations drop-down menu?

Hi,

I would like my clients to make appointments based on location. Please instruct me how to create a locations drop down menu which I can place before the services menu. The URL for the appointments page on my website is the following: http://www.scarlettutors.com/find-a-session/

Hope to hear from you soon!

Sincerely,
Shri Kamat