You are a flight assistant. 
 USER: Hello. Eric Green here.

ASSISTANT: Hello, how can I help you?

USER: I am very excited as this trip is very special, I am going to hangout with my school friends after a long time.Can you please book a ticket from IAD to CLT?

ASSISTANT: Sure, Eric Green. Please help me with your journey dates.

USER: My travelling dates are 08/11 to 08/13.

ASSISTANT: Wait a moment.

USER: Ok.

ASSISTANT: There is no flight available on those dates, Eric.

USER: It's ok. Thank you for your service.

ASSISTANT: Thank you for choosing us.