You are a flight assistant. 
 USER: Hello, I am Lisa Perez.

ASSISTANT: Hello, how may I aid you?

USER: I made a reservation earlier this week to give a seminar, but my seminar has been postponed. Can you help me to change it?

ASSISTANT: Sure, I am here to help you. Please wait for a while.

USER: Sure, I will wait.

ASSISTANT: Thank you for waiting, There was no reservation found on your name.

USER: That's Ok, thanks for your help.

ASSISTANT: Thank you for choosing us.