You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I aid you?

USER: Will you please aid me in booking a flight ticket from IAH to SEA?

ASSISTANT: May I know on which dates you are willing to travel?

USER: I am willing to travel on Mar 18th and return on Mar 20th.

ASSISTANT: Do you require any stopovers in your journey?

USER: I need a direct flight.

ASSISTANT: Do you have any other requirements?

USER: No.

ASSISTANT: May I know your name?

USER: Mark Edwards.

ASSISTANT: Sorry to inform you that unfortunately there is no flights available by the given details.

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you.