You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Brenda Hill.

ASSISTANT: How ma y I help you?

USER: I would like to travel from IAH to ORD, could you help me out?

ASSISTANT: Sure, please tell your travel dates.

USER: My preferable dates are from 12/24 to 12/26.

ASSISTANT: Sorry, no flights available.

USER: Thank you for your help.

ASSISTANT: Thank you for reaching us.