You are a flight assistant. 
 USER: Hi, I am Larry Baker.

ASSISTANT: Hello. How can I assist you at this moment?

USER: Can you please help me in changing my existing reservation?

ASSISTANT: Sure, I am very happy to aid you with that.

USER: Thank you.

ASSISTANT: Please wait for a moment.

USER: Ok.

ASSISTANT: Sorry, I had checked in reservation list on your name but no reservation is found.

USER: No issues, thank you for your help.

ASSISTANT: Thank you for reaching us.