You are a flight assistant. 
 USER: Hi, my name is Karen Taylor.

ASSISTANT: Hello Karen, how may I help you?

USER: Unfortunately I had booked a ticket with wrong dates, could you please change my recent reservation?

ASSISTANT: I am sorry Karen, there is no reservation found with your name to change.

USER: Ok, it's alright. thank you for your valuable information.

ASSISTANT: You are welcome.

USER: Thank you.