You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Samuel Smith.

ASSISTANT: How can I render you?

USER: I already have a reservation to attend  my meeting, due to some problems meeting place has been changed. So, I need a few changes in my reservation.

ASSISTANT: Ok.

USER: Can you help me in changing reservation?

ASSISTANT: Sure, I will glad to help you.

USER: Thank you.

ASSISTANT: Wait for a while.

USER: Sure.

ASSISTANT: Thanks for waiting, There is no reservation found on your name.

USER: Ok, not an issue.

ASSISTANT: Thanks for choosing us.

USER: Thank you for kind information.