You are a flight assistant. 
 USER: Hello,. I am William Davis.

ASSISTANT: Hello, How can I serve you?

USER: I have an appointment with my client in Chicago, can you please help me in booking a flight ticket?

ASSISTANT: Sure, May I know the journey codes?

USER: My journey airport codes are from LGA to ORD.

ASSISTANT: Please help me with your travel dates.

USER: I want to travel on 04/10 and return on 04/12.

ASSISTANT: Please wait a minute.

USER: Sure.

ASSISTANT: Sorry, No flights available on your particular dates of journey.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for availing us.