You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, may I know how best I can help you today?

USER: My name is Kathleen Walker. Can you help me to change the reservation which I had done last month?

ASSISTANT: Sure, I am here to help you in that.

USER: Ok, thank you for positive response.

ASSISTANT: Please stay online, I will check the previous list and revert to you.

USER: Ok, please take your own time.

ASSISTANT: We are sorry to say that, there is no active reservation found on your name.

USER: Ok, that is not a problem. Thank you for the information provided.

ASSISTANT: Thanks for choosing us, have a great day.