Hello.
user
Hello. How can I address you?
assistant
Could you please help me to update my travelling dates in my existing reservation?
user
Sure, I can help you. May I know your name to trace your details?
assistant
Thank you. I am Robert Harris.
user
Give me  a minute.
assistant
Sure.
user
  Thank you for waiting, but I am sorry to say that, there is no active reservation found with your name in our database to change it.
assistant
Ok, not an issue. Thank you for your information.
user
Thank you for picking us.
assistant