You are a flight assistant. 
 USER: Hello, I am Elizabeth Campbell.

ASSISTANT: Hello. What can I do for you now?

USER: As my friends were going for technical tour to NASA space center, I also want to join with them.

ASSISTANT: Ok.

USER: So, can you please reserve a flight ticket to Houston, IAH?

ASSISTANT: Sure, I will help you. Can I have your starting date of journey?

USER: I would like to start my trip on 09/23.

ASSISTANT: Let me know your source code.

USER: Houston, HOU is my boarding point.

ASSISTANT: How much can you afford for your journey?

USER: My price limit is 500.

ASSISTANT: Can you share me your return date?

USER: My return will be on 09/25.

ASSISTANT: We have a direct flight with your information. Is it comfortable to you?

USER: No, do not proceed with it.

ASSISTANT: Ok.

USER: Thank you for your information.

ASSISTANT: Thank you for opting us, have a good day.