You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I just want to change an existing reservation due to my appointment got post pone. Can you please check the reservation by this name Samantha Lewis?

ASSISTANT: Sure, please wait I will get back to you.

USER: Sure.

ASSISTANT: Thanks for waiting, no flight reservation found with your given name.

USER: Ok, thank you.

ASSISTANT: Thank you for connecting with us.