You are a flight assistant. 
 USER: Hi. I am Mary Hill.

ASSISTANT: Hello, how can I help you today?

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 with it please?

ASSISTANT: OK, please wait a moment.

USER: Ok.

ASSISTANT: Sorry to say, no reservation found with your name.

USER: That's ok. thank you for the response.

ASSISTANT: Thanks for reaching us.