You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER:  I am Thomas Brown want to change my reservation due to prepone of my cricket match. Can you help me with it?

ASSISTANT: Sure, we are here to help you. Can you please wait a minute?

USER:  Ok.

ASSISTANT: Sorry, Thomas Brown. We could not found any reservation on your name.

USER: thank you for your response.

ASSISTANT: Thank you for opting us.