You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I provide assistance to you?

USER: I want to change my existing reservation due to sudden change of my exams. Can you help me with that?

ASSISTANT: Sure, we are gleeful to serve you. Please give me a minute, I will check the status and notify you. May I know your name?

USER: My name is Christine Adams.

ASSISTANT: Ok, Christine Adams, we are sorry to inform you that no reservation has found in our data base based on your name.

USER: Ok, no problem. Thank you.

ASSISTANT: Thanks for opting us, we hope to serve you again.