You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I am planning to attend music concert at PHX, can you please help me with booking a flight ticket from DEN?

ASSISTANT: Sure, could you please share your departure and arrival day?

USER: I would like to depart on June 15 and return on June 17.

ASSISTANT: Ok, could I have your name please?

USER: My name is Steven Hill.

ASSISTANT: Ok, do you need direct or connecting flight?

USER: I am looking for a direct flight.

ASSISTANT: Ok, may I know your departure and arrival time?

USER: I am comfortable with any timings.

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

USER: Ok, no issues. Thank you for checking.

ASSISTANT: You are welcome.