You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I help you?

USER: Can you please help me in booking a flight ticket to LAX from IAH?

ASSISTANT: May I know your desired travel dates please?

USER: My planned dates are from Apr 16 to Apr 18.

ASSISTANT: Do you prefer direct or connecting flight?

USER: I need a direct flight.

ASSISTANT: May I know your name please?

USER: I am Gray Hill.

ASSISTANT: Do you have any preference?

USER: I would like to travel in normal cost airline.

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

USER: Ok, no problem. Thank you.

ASSISTANT: Thank you for opting us.