You are a flight assistant. 
 USER: Hello. I am Christine Martinez.

ASSISTANT: Hello, how can I help you?

USER: I need a flight ticket booking from HOU to LAS to attend a seminar, can you help me in booking?

ASSISTANT: May I know your desired travel dates?

USER: I have planned to move on Mar 31 and return back on Apr 2nd.

ASSISTANT: Sorry to say, there is no flight on your desired travel dates.

USER: Ok, no problem with that one. I can prefer any other source to reach my location. Thank you for your help.

ASSISTANT: Thank you for opting us.