You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello,.

USER: My name is Andrew Harris.

ASSISTANT: How may I assist you?

USER: I want to book a direct flight from TX - DFW. Can you please book a flight ticket with the fare of 200?

ASSISTANT: Sure, may I know your journey dates?

USER: My journey dates are from 09/27 to 09/29.

ASSISTANT: Can I know your destination point for further booking?

USER: My destination code is NV - LAS.

ASSISTANT: Thank you for the information, we are sorry to say that there is no flight found matching your specifications.

USER: Ok, no issues. Thanks for your response.

ASSISTANT: Have a good day.