You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I assist you?

USER: I am Ruth Mitchell. I want to change an existing  reservation due to sudden change in my trip.Can you help me?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Thanks for waiting, there is no reservation found on your name.

USER: No issue, Thank you for the information.

ASSISTANT: Thank you for choosing us.