You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to book a flight from DCA - JFK.

ASSISTANT: Sure, provide me your name to proceed further.

USER: Christopher Thomas here.

ASSISTANT: Can you let me know your journey dates?

USER: I will be travelling on 08/05 to 08/07.

ASSISTANT: There are no flights available at this moment.

USER: Ok, no issues. Thank you for checking.

ASSISTANT: Thank you.

USER: Most welcome.