You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you?

USER: Myself Timothy Clark, can you help me to change my reservation which is existing?

ASSISTANT: Please wait a while.

USER: Ok, I will wait.

ASSISTANT: Sorry to say, there is no reservation on your name in our database.

USER: Thank you for the information.

ASSISTANT: Thank you for opting us. Have a nice day.