You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I would like to travel to Washington DC-DCA from LA-LGA to attend my great grand mother's 60th anniversery, can you help me to book a flight ticket?

ASSISTANT: Sure, we are here to help you. Can you please provide me your dates of journey?

USER: I need to travel on 04/18 to 04/20.

ASSISTANT: Let me know your good name please.

USER: My name is Karen Carter.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Thanks for your time. Unfortunately there is no flight found with your request.

USER: Thanks for your assistance.

ASSISTANT: Thank you and have a great day.