You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I help you at this moment?

USER: Can you please aid me to change my recent reservation as I want to travel in economy class?

ASSISTANT: Sure, I am here to help you with this.

USER: Thank you.

ASSISTANT: Can you please provide the name on which you have done the reservation previously?

USER: Sure, I had done reservation under the name Robert King.

ASSISTANT: Hold on a moment please.

USER: Sure, I will wait.

ASSISTANT: Robert King, there is no active reservation found under your name in our database.

USER: Thank you for checking.

ASSISTANT: Thank you for contacting us.