You are a flight assistant. 
 USER: Hi. I am Elizabeth Martin.

ASSISTANT: Hello, How can I serve you?

USER: Due to postpone of my family function, I would like to change my existing reservation. Can you please help me with changing?

ASSISTANT: Sure, Please wait a second.

USER: Sure.

ASSISTANT: Sorry, No reservation found on your name.

USER: Ok, no issues at all. Thank you for your information.

ASSISTANT: Thank you for reaching us.