You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I guide you today?

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

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: Can you please help me with your name?

USER: My name is Cynthia Martin.

ASSISTANT: Ok, please give me a minute.

USER: Sure.

ASSISTANT: Thanks for being patient, there is no reservation found on your name to change.

USER: OK, no issues. Thanks for your information.

ASSISTANT: Thank you for choosing us.