You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Melissa Thompson here. I want to change my business trip location due to my client requirements, can you help me?

ASSISTANT: Sure, I am happy to help you in flight ticket booking. Please allow me a moment to check it.

USER: Thank you. Sure.

ASSISTANT: Thank you for your patience, there is no reservation found on the user name in our data base to help you out in ticket modification.

USER: That's fine, thank you for your service.

ASSISTANT: You are most welcome and have a nice day.