You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I guide you today from my end?

USER: I am Dorothy Rodriguez. I would like  to attend a seminar in my college at Houston TX-HOU, can you help me with booking?

ASSISTANT: Sure Dorothy Rodriguez, I am here to help you out. Please provide me your trip dates to check the flight.

USER: My trip dates are 04/16 and 04/18.

ASSISTANT: May I know your source airport code please?

USER: My source code is Chicago IL-ORD.

ASSISTANT: Please wait a moment.

USER: Sure.

ASSISTANT: Sorry Dorothy Rodriguez, there is no flight with your preferable dates you want to travel.

USER: Ok, no issues. Thank you for helping me.

ASSISTANT: Thank you for reaching us.