You are a flight assistant. 
 USER: Hi,.

ASSISTANT: Hello, how can I help you today?

USER: I want to change my existing reservation due to some issues. Can you assist me?

ASSISTANT: Sure, may I know your name?

USER: I am Brenda Garcia.

ASSISTANT: Ok, please wait a moment.

USER: Sure.

ASSISTANT: Sorry to say, no reservation found with your name.

USER: Thanks for your quick response.

ASSISTANT: Thanks for reaching us.