You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you better?

USER: Can you change my existing reservation?

ASSISTANT: Sure, I can change your reservation. Please provide the name on which you have done your reservation?

USER: My name is Alexander Baker.

ASSISTANT: I regret that there is no reservation found on your name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thank you for approaching us.