You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: As my planning to meet my friend was postponed. For this I have to change my existing reservation with the name of Samuel Harris.

ASSISTANT: Sure, Please wait for a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, there is no reservation found with your name.

USER: Not an issue. Thank you for aiding me.

ASSISTANT: Have a good day.