You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, do you need any help from us?

USER: I have booked a flight ticket in the last week but now the meeting was postponed. So, I just want to change the travel dates. Can you please help me to do that?

ASSISTANT: Sure, could I have your name please?

USER: Sharon White here.

ASSISTANT: Ok, please allow me a moment.

USER: Sure.

ASSISTANT: Sorry, there is no reservation with your name in our portal to make changes.

USER: Ok, no problem. Thank you.

ASSISTANT: You are welcome, have a great day.