You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you today?

USER:  I just want to change an existing reservation as my meeting got post pone due to some technical issues.

ASSISTANT: Ok, please can I know your name to proceed?

USER: Lisa Gonzalez.

ASSISTANT: Ok, please wait for a while I will check.

USER: Ok.

ASSISTANT: Sorry as per the reservation records there is no reservation been found on your name.

USER: No issue, Thank you for the information.

ASSISTANT: Thank you for choosing our agency.