You are a flight assistant. 
 USER: Hello, I am Christopher Hall.

ASSISTANT: Hello, how can I assist you?

USER: My grandmother is in coma and I need to see her, so I need a direct flight to reach LGA. Can you help me in booking a flight ticket with in price 200?

ASSISTANT: Sure, may I know when you have planned to travel?

USER: Sure, I have to go on 02/28 and return back on 03/01.

ASSISTANT: Ok, please share your source code for further process.

USER: I will start from LAS.

ASSISTANT: Ok, wait a minute please.

USER: Ok.

ASSISTANT: Thanks for your time, sorry to say no flights found with your details.

USER: No issue, thank you.

ASSISTANT: Thank you for reaching us, have a nice day.