You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I aid you?

USER: My friend has changed the tour plan to visit Detroit, I have previously reserved my ticket to Dallas, could you help me in changing the existing reservation?

ASSISTANT: May I know your name?

USER: My name is Debra Garcia.

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

USER: Ok, no issues.

ASSISTANT: Thank you for choosing us.

USER: Thank you for checking the information.