You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Thomas Williams.

ASSISTANT: How may I help you?

USER: Actually I booked the ticket on wrong date, could you help me in changing the existing reservation?

ASSISTANT: Sure, I will help you. Please wait a moment.

USER: Sure.

ASSISTANT: Thomas, there is no active reservation on your name in our database.

USER: That's ok.

ASSISTANT: Thank you for approaching us.

USER: Thank you for your time.

ASSISTANT: You are welcome.