You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Andrew Lee here. I would like to change my existing reservation. Can you help me?

ASSISTANT: Sure, can you be online for 2 minutes?

USER: Sure, take your time.

ASSISTANT: Sorry, there was no reservation found on your name.

USER: No problem, Thank you for your time and information.

ASSISTANT: Ok, thank you for opting us.