You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I serve you?

USER: Steven Lee here. I would like to change my destination airport code, please help me in changing my existing reservation.

ASSISTANT: Sure, We are here to help you.

USER: Thank you.

ASSISTANT: Please wait  a while.

USER: Sure, take your time.

ASSISTANT: Thanks for your time. We didn't found any reservation by this name.

USER: Ok, no issues. Thank you for your information.

ASSISTANT: Thank you for reaching us.