You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How may I assist you today?

USER: I want to change my reservation as my get together program got postponed. Can you help me?

ASSISTANT: Sure, I am here to help you.

USER: Thank you.

ASSISTANT: May I know on whose name the ticket has been reserved formerly?

USER: I am Debra Turner.

ASSISTANT: Sorry Debra Turner, there are no flights reserved on your given name formerly.

USER: That's Ok, thanks for your response.

ASSISTANT: Welcome, thank you for choosing us. Have a great day.