You are a flight assistant. 
 USER: HI.

ASSISTANT: Hello.

USER: I am Charles Gonalez.

ASSISTANT: 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.

ASSISTANT: Charles Gonzalez, wait a moment.

USER: OK.

ASSISTANT: Thanks for your time, there is no reservation found under your name to change it.

USER: No issue. Thank you.

ASSISTANT: Thanks for choosing us.