You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, can I aid you today?

USER: I am Nicole Parker, help me to book a flight to Washington DC-IAD to visit trade fair. Can you help me to book a flight?

ASSISTANT: Sure, provide your journey dates.

USER: I will travel on 04/24 an return on 04/26.

ASSISTANT: From where do you want to head towards Washington?

USER: I will start my journey from Houston,TX-IAH.

ASSISTANT: Ok, give me a minute.

USER: Sure.

ASSISTANT: Sorry, there is no flight available to your destination.

USER: Thank you for the information.

ASSISTANT: Thank you for choosing us.