You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you?

USER: Thomas Thomas here. I want to alter my reservation, due to postponement of concert to be held at the place where I wanted to visit, can you please take your some time for helping me?

ASSISTANT: Sure, please give me a minute so that I can check with your previous reservation details. Sorry, there is no reservation found with your name.

USER: It's ok.

ASSISTANT: Would you like to travel on any other dates?

USER: No, thank you for the  information.

ASSISTANT: Thank you, have a good day.