You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I be your helping hand today?

USER: I have got an invitation from NASA space center, so I would like to go there to gather some knowledge. Please assist me in booking a flight ticket from LAX.

ASSISTANT: Sure, we are glad to assist you.

USER: Thank you.

ASSISTANT: May I know your journey dates please?

USER: Sure, I am leaving on 11/23 and I will be back on 11/25.

ASSISTANT: Kindly ensure your destination point?

USER: Sure, it's HOU.

ASSISTANT: How much you can spend for airfare?

USER: I can afford up to 500.

ASSISTANT: May I know your good name please?

USER: Sure, I am Cynthia Moore.

ASSISTANT: Ok, please wait for a few minutes.

USER: Sure.

ASSISTANT: We are sorry to inform you that, we did not find any flights matching your specifications.

USER: Ok, I will search for alternative.

ASSISTANT: Thank you for reaching us. Have a good day.

USER: Anyway, thank you.