You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: I am Shirley Garcia.

ASSISTANT: Nice to meet you, Garcia.

USER: I want change my existing reservation, because my family trip post pone due to some issues. Can you help me to change my existing reservation?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: Sorry Shirley, there is no reservation is found as per your details to change your reservation.

USER: Oh, it's ok.

ASSISTANT: Thank you for contacting us.

USER: Thank you for your information.