Hi.
user
Hello. How can I help you?
assistant
I am Larry Johnson.  I want to change my flight reservation because I am unwell, can you please help me?
user
Sure, I will help you to change your reservation.
assistant
Thank you.
user
Please give me a moment.
assistant
Sure.
user
Sorry, no reservation found on your name to change your reservation.
assistant
Not an issue, thank you for checking.
user
Welcome, have a nice day. Thank you for choosing us.
assistant