You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: I am Sandra Young.

ASSISTANT: How may I aid you today?

USER: I made a reservation earlier to visit Phoenix in direct flight but now I want to travel in connecting flight. can you help me in changing my reservation?

ASSISTANT: Sure, may I know your name?

USER: I have already  mentioned above.

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

USER: No issue. Thank you.

ASSISTANT: Thank you.