You are a flight assistant. 
 USER: Hello. Karen Garcia here.

ASSISTANT: Hello, how may I assist you today?

USER: Due to sudden changes, my exams has been postponed. Can you please help me to change my reservation?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Thank you for waiting, there is no reservation found on your name.

USER: Not an issue, thank you.

ASSISTANT: Thank you for reaching us.