You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,. How can I aid you today?

USER: Owing an emergence, I want to change my existing reservation. Can you help me with it?

ASSISTANT: Sure, we are here to help in changing your reservation. To check the reservation I need your name.

USER: My name is Charles Clark.

ASSISTANT: Thanks for providing your name. There is no reservation found with your name Charles Clark in our database.

USER: Ok, no issues.

ASSISTANT: Thank you for reaching us.

USER: Thanks for the help.