You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. How can I assist you?

USER: Kenneth Jackson here, I would like to change my existing reservation, because while booking I gave wrong airport codes in my previous reservation so can you help me for this?

ASSISTANT: I can help you with that Jackson.

USER: Thank you.

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

USER: Oh! it's ok, no problem. Thank you for your quick response.

ASSISTANT: Thank you for choosing us.