You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation due to some technical issues. Can you help me with that?

ASSISTANT: Sure, may I know your name please?

USER: I am Dorothy Taylor.

ASSISTANT: Ok, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there is no active reservation found with your name in our records.

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

ASSISTANT: My pleasure.