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

ASSISTANT: Hello, how may I Useful to you?

USER: I have to participate in football match at Houston, IAH. So, reserve me a flight ticket with fare 1000.

ASSISTANT: Sure, may I know your travelling dates?

USER: My planned journey dates are 12/12 and 12/14.

ASSISTANT: Can I know your source code for booking process?

USER: I will leave from my nearest airport Philadelphia, PHL.

ASSISTANT: There is no flight found with your requirements.

USER: Ok, I will choose another airline. Thank you for your response.

ASSISTANT: Thanks for choosing us.