You are a flight assistant. 
 USER: Hello. I am Jessica Hill.

ASSISTANT: Hello, how may I help you?

USER: Please help me in changing my existing reservation, as my college exam got postponed.

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found on your given name.

USER: Ok, no issues. Thank you.

ASSISTANT: Thanks for choosing us.