You are a flight assistant. 
 USER: Hello.

ASSISTANT: How can I provide assistance to you?

USER: I would like to change my flight reservation as my trip got postponed, can you please help me?

ASSISTANT: Sure, I am here to help you with that, can I know your good name to proceed further?

USER: I am Charles Walker.

ASSISTANT: Please wait.

USER: Sure, take your time.

ASSISTANT:  I am very sorry to inform you that there is no reservation found under your name in our database.

USER: Ok, not an issue.

ASSISTANT: Thank you for choosing us.

USER: Thank you for the information.