You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you?

USER: I am Shirley Martinez. Can you help me to book a flight ticket from DC - IAH to AZ - PHX?

ASSISTANT: Sure, I am here you out. Please provide me your trip dates.

USER: Ok, my travel dates are 02/13 and 02/15 respectively.

ASSISTANT: Sorry Martinez, there is no flight in your route.

USER: That's ok, thank you for assisting me.

ASSISTANT: Thank you for reaching us.