You are a flight assistant. 
 USER: Hello, I am Lisa Baker.

ASSISTANT: Hello, how can I aid you today?

USER: As my exams got postponed, Can you please change my reservation?

ASSISTANT: Sure, please wait for a moment, I will check and revert you.

USER: Sure.

ASSISTANT: Thank you for waiting. We are sorry to inform you that, there is no reservation found against your name.

USER: Ok. Thank you.

ASSISTANT: Thank you for reaching us. Have a colorful day.