You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I assist you for today?

USER: I want to change my trip dates because I had an important meeting, so that I am unavailable to catch the flight. Can you alter my ticket?

ASSISTANT: Ok, please provide your name to check the existing reservation.

USER: Sure, the previous reservation is done under the name John Mitchell.

ASSISTANT: Sorry, there is no reservation on your name to change. Do you have any other requirements?

USER: Ok, no problem, I will search  any other way.

ASSISTANT: Ok, thank you for using our service. Have a great day ahead.

USER: Thank you for your information.

ASSISTANT: Most welcome.