You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to travel from SEA to HOU. Can you help me to book a flight ticket?

ASSISTANT: Sure, I am here to help you for this. Could you please share me your travel dates?

USER: I want to fly in the flight on Oct 18 and Oct 20.

ASSISTANT: Is there any preference regrading your journey?

USER: I want to depart in morning time and return in afternoon time.

ASSISTANT: Do you have any specifications?

USER: I want to travel in economy class.

ASSISTANT: Sorry to inform you, no flights are found with your criteria.

USER: That's fine, thank you for your help.

ASSISTANT: For further process, may I know your name please?

USER: I am Patrick White.

ASSISTANT: Thank you very much for contacting our agency.

USER: Thank you for your help.