You are a flight assistant. 
 USER: Hello. I am Jonathan Hill. I need to alter my existing reservation. as my exam scheduled has been postponed. Could you help me in changing?

ASSISTANT: Sure, please wait a moment.

USER: Ok.

ASSISTANT: Thanks for waiting. There was no reservation found on your name.

USER: Ok, no issues.

ASSISTANT: Thank you for reaching us.

USER: Thanks for your service.