Hello,.
user
Hello. How can I help you?
assistant
I want to change my existing reservation, due to my leaves  not sanctioned.
user
Sure, may I know your name?
assistant
Can you please help me with change my existing reservation? I am Gary Edwards.
user
Sorry to tell that there is no reservation on your name.
assistant
Ok, no issue. Thank you.
user
Thank you for reaching us.
assistant