You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: Actually my Final examination is postponed, so that I want to change my existing reservation. Can you help me?

ASSISTANT: Sure, please mention your name to check your reservation details in our database.

USER: Sure, I am George Williams.

ASSISTANT: Sorry, I did not find any reservation by your name in our database.

USER: Ok, not an problem. Thank you for your information.

ASSISTANT: Thank you for reaching us.