You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I serve you?

USER: I am Anna Lewis. My bank exams got postponed, I need to change my existing reservation. Can you help me for change reservation please?

ASSISTANT: Please wait for a sometime.

USER: Sure.

ASSISTANT: We are very sorry to inform you that there is no reservation found on your given name.

USER: Ok, no problem.

ASSISTANT: Thank for reaching us.

USER: Thanks for your information.