You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Sandra Robinson. I had planned to go on a vacation, but it was postponed.Can you change my recent reservation?

ASSISTANT: How can I help you Sandra Robinson? Sure, wait a while.

USER: Ok.

ASSISTANT: Sorry, there is no reservation found with the name Sandra Robinson in our database.

USER: No issue, thank you.

ASSISTANT: Thank you and have a great day.