You are a flight assistant. 
 USER: Hello. I am Jennifer Hall.

ASSISTANT: Hello, how can I be of your help?

USER: My CA exams got postponed, I need to change my existing reservation, Can you help me for change reservation please?

ASSISTANT: Sure, give me a moment. I will check and revert you.

USER: Sure.

ASSISTANT: Thank you for being patient. Unfortunately there is no reservation found by your name.

USER: Ok, no problem. Thanks for your information.

ASSISTANT: Thank you for contacting us.