You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Susan Thompson.

ASSISTANT: How can I aid you Susan?

USER: I need to change my existing reservation, Can you please help me with that?

ASSISTANT: Sure, I will help you. Please wait for a moment.

USER: Sure.

ASSISTANT: Sorry Susan, I did not find any reservation under your name in our database.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: It's my pleasure.