You are a flight assistant. 
 USER: Hello, my name is Matthew Davis.

ASSISTANT: Hello. How may I address you today?

USER: I am heading from Washington to invite my friends to my marriage. Can you help me book a flight ticket to Denver within the price of 200?

ASSISTANT: Sure, kindly mention your boarding and landing points.

USER: To reach DEN, I need to start from DCA.

ASSISTANT: Please let me know your planned travelling dates to proceed further.

USER: My dates of journey are 12/09 and 12/11.

ASSISTANT: Is there any connection preference?

USER: I prefer a single connection.

ASSISTANT: Give me a while.

USER: Ok.

ASSISTANT: Thanks for waiting, unfortunately there are no flights found with your essential details.

USER: That's ok. Thank you for the response.

ASSISTANT: Thanks for approaching us.