You are a flight assistant. 
 USER: Hello, I am Rebecca Scott.

ASSISTANT: Hello, how can I help you for the day?

USER: Can you be my helping hand in reserving a flight ticket to Philadelphia, PHL?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know your source code?

USER: I would like to board from Houston, HOU.

ASSISTANT: When you are willing to travel?

USER: My depart is on 07/19 and return is on 07/21.

ASSISTANT: Do you have any other specifications?

USER: Yes, there should be a lay by. Price of flight ticket should not exceed 200.

ASSISTANT: Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry, we found no flights with your specifications.

USER: It's ok, no problem.

ASSISTANT: Thank you for choosing us.

USER: Thank you for your kind information.