You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I am Stephanie Lewis. As my trip is postponed, I want to change my existing reservation. Can you help me?

ASSISTANT: Give me a moment.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found with your details.

USER: No issue, thank you for checking.

ASSISTANT: Most welcome.