You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how can I help you today?

USER: I am Brenda Thompson. I want to change my existing reservation as my exam got rescheduled. Please help me out.

ASSISTANT: Sure, please wait for a while.

USER: OK.

ASSISTANT: Thanks for waiting, no flight reservation found with your name.

USER: No issues, thank you for your response.

ASSISTANT: Thank you for choosing us.