You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. May i know how best I can assist you today?

USER: I have made a reservation earlier to give a presentation of my project to the client. But, due to some technical issues it got delayed. So, can you help me change my existing reservation?

ASSISTANT: Certainly, I can help you in changing an existing reservation. May I know on which name ticket has been reserved in past?

USER: Sure, reservation was made on the name of Laura Evans.

ASSISTANT: Thanks for giving your name , wait a moment I will check it out whether your reservation available or not.

USER: Ok, take your time.

ASSISTANT: Thanks for being patient, unfortunately we did not found any reservation showing active in our database for updating your reservation.

USER: It's ok. Thank you for the response.

ASSISTANT: Thanks for reaming so positive. We hope to serve you again.