You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you?

USER: I have to change my travelling dates in  my previous reservation due to my leaves got shifted to another  dates. So please help me with that.

ASSISTANT: Sure, can I know your name please?

USER: Thank you. Please check my reservation with my name Raymond King.

ASSISTANT: Sorry, there is no reservation found on your name.

USER: Oh! It may not be booked properly due to server issues while booking. Anyway, thank you for your time.

ASSISTANT: Thank you for approaching us.

USER: Most welcome.