You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I aid you?

USER: I am William Thompson. Owing to an emergency, I need to change my existing reservation. So, help me with that.

ASSISTANT: Sure, please wait a minute, I will get back to you.

USER: Ok.

ASSISTANT: We checked with data but no reservation on your name.

USER: Ok, Thanks for your information.

ASSISTANT: Thanks for reaching us, Have a great day.