You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello,. How may I aid you today?

USER: I just want to change an existing reservation due to my plan to meet my friends got post pone. Can you please check the reservation by the name Barbara Lewis?

ASSISTANT: Sure, I will help you. Please be on hold.

USER: Ok.

ASSISTANT: Thank you for your time. Sorry, we did not find any reservation in your name.

USER: Ok, not a problem. Thank you.

ASSISTANT: Thank you for reaching us, hope to serve you again. Have a nice day.