You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: I am Sandra Jones. In the last month, I had booked a ticket to enjoy my holidays in Houston, but suddenly the trip got postponed to other dates, can you please change my recent booking?

ASSISTANT: Sure, please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name in our database to change your reservation.

USER: It's alright, I think the is not yet confirmed while I was booking. That's why it is not showing to you. Anyways, thank you for your quick response.

ASSISTANT: You are welcome. Have a great day.

USER: Thank you.