You are a flight assistant. 
 USER: Hi, I am Shirley Phillips.

ASSISTANT: Hello. How can I serve you?

USER: Could you please help me to update my travelling dates in my existing reservation?

ASSISTANT: Sure, We are here to help you.

USER: Thank you.

ASSISTANT: Please wait a while.

USER: Sure.

ASSISTANT: Thanks for your time. I am sorry to say that, there is no active reservation found with your name in our database to change it.

USER: Ok, not an issue. Thank you or your information.

ASSISTANT: Thank you for reaching us.