You are a flight assistant. 
 USER: Hi, I'm Donald Scott.

ASSISTANT: Hello Scott, how may I help you?

USER:  My convocation ceremony is being held in Phoenix, can you help me in booking a ticket from DTW to PHX?

ASSISTANT: Sure, please provide your itinerary dates.

USER: My planned dates of travelling are from 12/13 to 12/15.

ASSISTANT: Sorry, no flight is available for you.

USER: It's ok, no problem.

ASSISTANT: Thank you for availing our services.

USER: Thank you for helping me.