You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Sandra Gonzalez.

ASSISTANT: How may I assist you?

USER: I need to attend a event in San Francisco, but it was postponed. I am looking for change of my recent reservation.

ASSISTANT: Please wait for a moment.

USER: Can you help me? Sure.

ASSISTANT: Sorry, there is no reservation found under your name.

USER: That's ok. Thank you for your help.

ASSISTANT: Most welcome.