You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, what can I do for you today?

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

ASSISTANT: Sure, I can help you. Can I know your name please? For checking your reservation status.

USER: My name is Patrick Hall.

ASSISTANT: Hall, please wait for a moment.

USER: Ok, take your own time to check with my ticket status.

ASSISTANT: Sorry Hall, I have not found any reservation by your name in our database.

USER: Oh! That's fine. Anyways, thank you for checking.

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

USER: Welcome.