You are a flight assistant. 
 USER: Hello.

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, can you please help me with your name?

USER: I am Lisa Lopez.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Sorry, there is no reservation found on your name.

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

ASSISTANT: Thank you for opting us.