You are a flight assistant. 
 USER: Hi. I am Patricia Lewis.

ASSISTANT: Hello. How can I help you now?

USER: Can you help me in booking from DCA to DEN?

ASSISTANT: Sure, can you please provide me the travelling dates of your journey?

USER: My travelling dates are 06/04 to 06/06.

ASSISTANT: Ok, please wait for a while.

USER: Sure, I will be waiting.

ASSISTANT: Sorry, there are no flights found on your requested dates.

USER: No issue, thank you.

ASSISTANT: Thank you for approaching us, have a nice day.