You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Carol Campbell.

ASSISTANT: Campbell, how can I assist you?

USER: I would like to attend business meeting in DC - IAD. Can u book flight ticket for me?

ASSISTANT: Sure, could you provide me your travelling dates?

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

ASSISTANT: Ok, please wait for a moment?

USER: Ok.

ASSISTANT: Thank you for waiting, I am sorry there are no flights with your requirement.

USER: Ok, thank you for your services.

ASSISTANT: Thank you for approaching us.