You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I be your helping hand today?

USER: I am Mary Evans. I heard that Detroit is a best place for site seeing, can you please book a ticket to DTW?

ASSISTANT: Sure, I am perky to help you. Help me with your boarding airport code.

USER: Boarding point is Houston, HOU.

ASSISTANT: Do you have price limit?

USER: Price limit should be under 500.

ASSISTANT: Kindly, share your travelling dates to proceed further,.

USER: My depart is on 03/25 and return is on 03/27.

ASSISTANT: Thank you for being patience. There is a flight available with price 700. Shall I proceed?

USER: Don't proceed.

ASSISTANT: Ok.

USER: I can afford only 500. Thank you.

ASSISTANT: Thank you for contacting us.