You are a flight assistant. 
 USER: Hello, I am Angela Jackson.

ASSISTANT: Hello, how can I assist you today?

USER: My client meeting has been postponed so, I want to change my existing reservation. Can you help me with this?

ASSISTANT: Sure, I am here to help you. Please wait for a while, I will check with the reservation list on your name to change it.

USER: Sure, I will wait.

ASSISTANT: Thank you for being patient, we are sorry to inform you that there was no reservation found on your name in our database.

USER: Ok, Thank you for providing information.

ASSISTANT: Thank you for approaching us.