You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Jerry Collins.

ASSISTANT: How can I assist you at this moment?

USER: Due to some personal issues, I would like to change my existing reservation to some other dates. Can you help me?

ASSISTANT: Sure, I will help you in changing your reservation. Please be on hold for a moment.

USER: Sure, take your time.

ASSISTANT: Jerry Collins, there is no active reservation found under your name in our database.

USER: It's ok, thank you for the information.

ASSISTANT: Thank you for utilising our service.