You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you?

USER: By mistake I have booked a ticket to Los Angels with wrong dates, can you please help me in changing my recent reservation details?

ASSISTANT: Sure, may I know your good name please?

USER: Sure, my name is Anna Clark.

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

USER: Oh! May be I have done a wrong booking, I'll recheck it once and get back to you later. Thank you anyways.

ASSISTANT: Thank you for approaching us.