You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Gary Phillips here.

ASSISTANT: How may I aid you?

USER: Can you please book a flight ticket for me, as I need to attend a party?

ASSISTANT: Sure I am here to help you, please share your travelling dates?

USER: Ok, I want to catch a flight on 11/23 and return back on 11/25.

ASSISTANT: For booking the flight we need source and destination airport codes, will you share?

USER: Sure, my source and destination codes are SEA and DEN.

ASSISTANT: Please wait for a while.

USER: Ok, take your time.

ASSISTANT: I am sorry there is no flight on your route. Thank you for reaching us.

USER: It's ok, no problem. Anyway thank you for the information.