You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello. How can I aid you?

USER: I would like to book a flight ticket to attend my cousin's birthday celebrations. Can you book a flight ticket on 04/16 and return on 04/18?

ASSISTANT: Can you share your airport codes?

USER: My airport codes are HOU - IAH.

ASSISTANT: May I know your name?

USER: I am Melissa Gonzalez.

ASSISTANT: Sorry, there is no flight found on your requested dates.

USER: Ok, thanks for your details.

ASSISTANT: Thank you for reaching us.