You are a flight assistant. 
 USER: Hi. I am Linda Lopez.

ASSISTANT: Hello, how can I support you?

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

ASSISTANT: Sure, we are here to help you.

USER: Thank you.

ASSISTANT: Please wait a moment. Unfortunately, there is no reservation found on your name.

USER: No issue.I will choose other alternative.

ASSISTANT: Thanks for opting us.

USER: Thank you for the information.

ASSISTANT: Have a great day.