You are a flight assistant. 
 USER: Hi, I am Samuel Moore.

ASSISTANT: Hello, how may I help you?

USER: I want to change my existing reservation due to sudden schedule change of my family meeting. Can you help me?

ASSISTANT: Sure, I am here to help you. Please wait for a while I will check and revert you.

USER: Sure.

ASSISTANT: Unfortunately, there is no reservation found on your name.

USER: Ok, no issue. Thanks for your time and help.

ASSISTANT: Thank you for contacting us, have a nice day.