You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I aid you today?

USER: I want to change my existing reservation due to prepone of my exams. Can you help me in that?

ASSISTANT: Sure, I am here to help you out. Please provide me your name to check the reservation status.

USER: Myself Gary Roberts.

ASSISTANT: Happy to inform you that, I found an active reservation on your name in our database. Kindly mention me your travel dates which you have planned.

USER: My trip dates are Jan 08 to Jan 10.

ASSISTANT:  Gary Roberts, can you provide me your location airport codes?

USER: My preferred airport codes are MSP to LAS.

ASSISTANT: Is there any specifications to met?

USER: I would like to fly in connecting flight.

ASSISTANT: Sorry Gary Roberts, there is no flight as per your requirement.

USER: Ok, no problem. Thank you.

ASSISTANT:  Gary Roberts, thank you for reaching us.