You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: My name is David Carter. I am planning to book a flight ticket to meet my friend in Atlanta. Can you help me for booking a flight ticket from DEN to ATL?

ASSISTANT: Sure, can I know your travelling dates?

USER: My travelling dates are 07/10 and 07/12.

ASSISTANT: Sorry, there are no flights are available for given schedule.

USER: That's ok, thank you for checking.

ASSISTANT: Thank you for reaching us.

USER: Welcome.