You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I aid you?

USER: I want to change dates in my existing reservation, can you please help me?

ASSISTANT: Sure, can I have your good name to check your reservation?

USER: The name on the ticket is David Young.

ASSISTANT: Can you please wait for a moment, I will check with your reservation.

USER: Sure, I will wait.

ASSISTANT: Thank you for waiting. Here, there is no active reservation have been found under your name in our database to amend it.

USER: Not an issue, anyway thank you for checking.

ASSISTANT: Thank you for reaching us with a query.