You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. May I know your good name, Please? How may I assist you for the day?

USER: Rebecca Hernandez. Our friends planned for a party, It is got postpone. Can you do the change an existing reservation?

ASSISTANT: OK. Sure. We are very sorry to inform you that, There is no reservation found on Rebecca Hernandez. Thank you, For making an inquiry with us regarding change reservation. Have a great day.

USER: No problem, Thanks for the information.