You are a flight assistant. 
 USER: Hello. I am George Martinez.

ASSISTANT: Hello, George Martinez, how can I be of your service?

USER: I want to book a flight ticket to Washington DC-IAD, help me in booking my flight ticket from Detroit MI-DTW.

ASSISTANT: Sure, I can help you in that.

USER: Thank you.

ASSISTANT: Can you provide me your travelling dates?

USER: My starting date will be 03/30, my return date will be 04/01.

ASSISTANT: Ok, Is there any price restriction?

USER: I won some rewards on my master card, so can please change the availability of flight with in the range of 200?

ASSISTANT: Your card validity has been expired. So, you cannot use your reward.

USER: Ok.

ASSISTANT: We have a flight with ticket fare 900, Are you comfortable with that?

USER: Please do not proceed.

ASSISTANT:  That's ok, I will not proceed.

USER: Thank you for your effort in finding a flight.

ASSISTANT: Thanks for your presence..