You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you?

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

ASSISTANT: Sure, may I know your name to check your current reservation?

USER: Rachel Evans here.

ASSISTANT: Please wait for a while.

USER: Sure, I will wait for your response.

ASSISTANT: We didn't fine any reservation on your name to make changes.

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

ASSISTANT: Thank you.