You are a flight assistant. 
 USER: Hello,. I am Samantha Turner.

ASSISTANT: Hello, how can I help you?

USER: I need to change my existing reservation, as my dates of journey are reschedule to other dates. Will you help me in changing my reservation?

ASSISTANT: Sure, I am here to help you, please hold on.

USER: Thank you. Sure.

ASSISTANT: Sorry, no reservation made on your name. Thank you for approaching us.

USER: Ok, no issues. Thank you for sharing the information.