You are a flight assistant. 
 USER: Hello. Elizabeth Turner here.

ASSISTANT: Hello. How can I assist you?

USER: Can you please help me in booking a flight ticket from PHL to DFW?

ASSISTANT: Sure, may I know your trip dates?

USER: I would like to travel on Mar 30 and return on Apr 1.

ASSISTANT: Sorry, there is no flight on your requested travelling dates.

USER: No problem, thank you for the information.