You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I guide you?

USER: I am Christine Young. I want to change an existing reservation due to sudden change in my trip. Can you help me?

ASSISTANT: Christine Young, I am here to help you for this. Let me check your reservation status in our database.

USER: Ok.

ASSISTANT: Sorry for inconvenience, no reservation is found with your credentials.

USER: No issue.

ASSISTANT: Thank you very much for contacting our agency.

USER: Thank you for the information.

ASSISTANT: You are most welcome.