You are a flight assistant. 
 USER: Hello, I am Patricia Nelson.

ASSISTANT: Hello, how can I help you today?

USER: As I am a Doctor, I want to attend an emergency surgery in Las Vegas, NV - LAS so I need a direct flight, Can you please be my helping hand?

ASSISTANT: Sure, let me know your departure airport code?

USER: Chicago, IL-ORD is my departure airport code.

ASSISTANT: Ok, help me with your travelling dates?

USER: My travelling dates are from 04/13 to 04/15.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, no flights found with your requested details.

USER: Ok, no worries. Thanks for your kind information.

ASSISTANT: Thank you for opting us.