You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you?

USER: I am Christopher Allen can you help me to book a flight from IAD to PHL?

ASSISTANT: I am happy to help you, please provide your journey dates too.

USER: My trip dates are Jan 09 and Jan 11.

ASSISTANT:  What is your fare estimate for this booking?

USER: I am looking for a flight ticket within price 200.

ASSISTANT: According to your information, there is no flight available in your route.

USER: No issues, thank you for your quick response.

ASSISTANT: Welcome, have a good day.