You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: I am planning to travel from HOU to ORD, can you please help me in flight booking?

ASSISTANT: Let me know your travel dates.

USER: I want to fly on Sept 05, return on Sept 07.

ASSISTANT: Is there any airline preference?

USER: No.

ASSISTANT: Do you have any class preference?

USER: No, I am comfortable with any class.

ASSISTANT: Can I know your name?

USER: My name is Katherine Lee.

ASSISTANT: Sorry, no flights found for your travelling dates.

USER: No problem, thank you.

ASSISTANT: Thank you.