You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: Elizabeth Clark here. I was made a reservation earlier in this week. I want to make some changes in that. Can you please help me for changing the reservation?

ASSISTANT: Sure, I am glad to help you. Please stand by.

USER: Ok.

ASSISTANT: Thanks for being on hold. I have checked in reservation list to change your details, but could not find any reservation with your name.

USER: Anyway, thank you for the information.

ASSISTANT: Thank you.