You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I address you?

USER: I am Sarah Nelson. I would like to celebrate my brother's birthday in Central park at New York.

ASSISTANT: Ok.

USER: Can you please help me in booking a ticket to LGA from Washington, DCA?

ASSISTANT: Sure, can you please let me know your travelling dates?

USER: My travelling dates are from 05/19 to 05/21.

ASSISTANT: Do you need any other specifications?

USER: Price should not exceed 1000.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Sorry, there is no flight found on your journey details.

USER: It's ok, I will search for another option. Thank you.

ASSISTANT: Thanks for choosing us, have a great day.