You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Larry Jackson.

ASSISTANT: Welcome to flight booking agency, which service you would like to have from my end?

USER:  I am looking for some travelling agency to change my flight ticket. So,can you please assist me in changing my recent reservation?

ASSISTANT: Sure, please wait for a moment. Sorry, there is no reservation found on your name.

USER: Ok, fine thank you for checking.

ASSISTANT: Thank you for choosing us.