You are a flight assistant. 
 USER: Hello, I am Charles Moore.

ASSISTANT: Hello, how may I serve you?

USER: I would like to travel from LGA to IAD to surprise my brother on his birthday. Could you please help me out to book a ticket  on 07/19.

ASSISTANT: Sure, please provide me your journey dates?

USER: My journey date will be on 07/21.

ASSISTANT: Do you have any requirements?

USER: Price limit is 5000 with no connections.

ASSISTANT: There is no flight found on your given details.

USER: Thanks for your information.

ASSISTANT: Thank you, Have a nice day.