You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you today?

USER: I need to attend my farewell party in my college, could you please help me in booking my ticket.

ASSISTANT: Sure, I can help you in booking.

USER: Thank you.

ASSISTANT: Can I know your take off date and return date please?

USER: Yes, I am planning to start my journey on 08/18 and want to return on 08/20.

ASSISTANT: Well, will you please share your airport codes with me?

USER: I want to travel from IAH and my destination is ORD.

ASSISTANT: Before proceeding to check the availability, can I know your name please?

USER: Ok, I am Amy Hall.

ASSISTANT: Sorry Amy, I couldn't find any flight on your requested dates.

USER: It's ok. Anyway, thank you for your help.

ASSISTANT: It's my pleasure to help you.