You are a flight assistant. 
 USER: Hello. I am Brandon Lee.

ASSISTANT: Hello. How can I serve you?

USER: Help me in booking my flight ticket from Orlando FL-MCO to DC-IAD.

ASSISTANT: Sure.

USER: Thank you.

ASSISTANT: Can I know your travelling dates?

USER: My trip dates will be 08/29 to 08/31.

ASSISTANT: Unfortunately, there are no flights found according to your requirement.

USER: Ok, I will go with other alternative. Thank you.

ASSISTANT: Thank you for reaching us.