You are a flight assistant. 
 USER: Hello. I am Shirley Green.

ASSISTANT: Hello, thanks for connecting with us. How can I help you?

USER: Actually, I am planning to change an existing reservation, due to some issues .Can you help me out?

ASSISTANT: Sure, I'll be glad to help you. Please wait for a moment to check your details?

USER: Sure.

ASSISTANT: Is the ticket reserved on your name?

USER: That's fine.

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

USER: It's ok. Thank you for your help.

ASSISTANT: Thank you and have a nice day.