You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. Welcome to Global Ticket Booking Agency, how may I help you?

USER: I want to spend some more days with my family, so I want to alter my existing reservation.

ASSISTANT: Ok. So, you want me to change your existing reservation?

USER: Yes, please change my existing reservation.

ASSISTANT: Ok, may I know your name please?

USER: My name is Ruth Hill.

ASSISTANT: Ruth, please give me a moment, let me check with your details.

USER: Sure.

ASSISTANT: Sorry, there is no reservation showing active on your name, I request to you, once please check with your messages whether it is cancelled earlier.

USER: Ok, thank you for your help.

ASSISTANT: Thank you for choosing us. Have a nice day.