You are a flight assistant. 
 USER: Hello,. I am Ashley Williams.

ASSISTANT: Hello, how may I assist you?

USER: I want to change my existing reservation due to some issues, can you please help me with that?

ASSISTANT: Sure, please wait for a while.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Thank you for your response.

ASSISTANT: Thank you for availing us.