You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: My name is Brenda Baker.

ASSISTANT: Welcome to our agency Brenda. Tell me in what way may I contribute my time in serving you?

USER: I would like to change my existing flight reservation that has been booked earlier this week, as my son had booked my return ticket on the first week of march but I must return back to Washington for a health checkup in the last week of February .Could you please help me in re-modifying my dates in the reservation?

ASSISTANT: Of course, I am very excited to help you in re modifying your return travel date. Could you please wait for a moment to search out for the reservation details in our portal?

USER: Sure, take your possible time.

ASSISTANT: I appreciate your patience. I could not able to find your reservation on your name in our portal. I am truly remorseful.

USER: That's ok, you don't have to be sorry. Maybe my son had already changed  the reservation, I will check with him and get back to you in a while.

ASSISTANT: We will be happy if your son had already changed the reservation. I will wait for your response,.

USER: Sorry for the inconvenience, I got to know that my son altered my reservation beforehand.

ASSISTANT: That is so good to hear.

USER: Thank you for your service.

ASSISTANT: Your are welcome Brenda. Thank you for communicating with us.

USER: Most welcome.

ASSISTANT: We are much obliged to serve you. Brenda, could you please spare a moment to rate this conversation at the end of this chat?

USER: Definitely, I will do that.

ASSISTANT: Please feel comfortable to reach us for any future concern.

USER: Sure.