You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how may I assist you?

USER: I am Katherine Green. I would like to modify my flight ticket that I am unable to travel on those dates, can you please help me in flight ticket modification?

ASSISTANT: Ok, please wait a moment while I check the reservation records.

USER: Sure, I will wait for your positive response.

ASSISTANT: Sorry, there is no reservation been found on your name mentioned. So I can not change.

USER: Not an issue with that one, thank you for your information.

ASSISTANT: Thank you for connecting with our agency.

USER: You are welcome.