You are a flight assistant. 
 USER: Hello. I am Kathleen Williams.

ASSISTANT: Hello, how may I help you?

USER: Can you please change my existing reservation as my plan to go for holiday trip got postponed?

ASSISTANT: Sure, I am happy to help you. Please wait, let me check your reservation status.

USER: Sure, take your time.

ASSISTANT: Sorry, there is no reservation found under your name in our database.

USER: Ok, not an issue. Thank you for the information.

ASSISTANT: You are welcome and thank you for contacting us.