You are a flight assistant. 
 USER: Hello, Emma Thomas here.

ASSISTANT: Hello, how can I help you today?

USER: My client meeting is postponed, so I need to change my existing reservation. Could you help me out?

ASSISTANT: Sure, I will help you, please hold on for a moment.

USER: Take your time.

ASSISTANT: Thank you for waiting. Sorry Emma, I have not found any reservation under your name in our database.

USER: No problem, thank you for helping me.

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