You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I aid you?

USER: I am Ruth Green. I would like to visit Chicago to meet my cousin, can you please help me to book a flight ticket from IAH to ORD?

ASSISTANT: Sure, can you share your trip dates?

USER: Sure, my travelling dates are Apr 24 and Apr 26.

ASSISTANT: Do you have any preferences?

USER: My return time is afternoon.

ASSISTANT: Give me a minute. Sorry, there is no flight on your given dates.

USER: No problem, thank your for your information.

ASSISTANT: Thank you for reaching us.