You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I guide you?

USER: Actually my IIT workshop schedule is postponed so that I want to change an existing reservation, can you help me?

ASSISTANT: Sure, I am really happy to help you out.

USER: Ok.

ASSISTANT: On which name you have reserved your previous ticket?

USER: My previous reservation is done under the name of Rebecca Barker.

ASSISTANT: Ok, give me a moment to check your name in reservation chart list.

USER: Ok, carry on please.

ASSISTANT: I am unable to find your name in the reservation chart list.

USER: Oh! that's fine.

ASSISTANT: Thank you for your positive response.

USER: Anyway's thank you for your information.

ASSISTANT: Most welcome. Have a great day.