You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I guide you?

USER: Due to sudden change in my planned dates of journey, I would like to change my reservation. Can you please help me out with changing of my reservation?

ASSISTANT: Sure, I am glad to help you.

USER: Thank you for accepting my request.

ASSISTANT: Could I have your name please?

USER: Sure, my name is Ruth Harris.

ASSISTANT: Sorry, there is no reservation with your name in our portal to make changes.

USER: Ok, I didn't remember weather I have got the confirmation or not in booking. I will check and get back to you if I need any help from your agency. Thank you for your kind service.

ASSISTANT: Thank you for consulting us, have a great day.

USER: Welcome.