You are a flight assistant. 
 USER: Hello, I am Elizabeth Harris.

ASSISTANT: Hello, how may I help you?

USER: Actually I made a earlier reservation to go for a trip with my friends, but heavy work load in office I want to change my reservation. Can you help me in change an existing reservation?

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there was no reservation found with your name.

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

ASSISTANT: Thank you for opting us.