You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How can I assist you today?

USER: I have to change my trip dates, so please help me in changing my ticket.

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: On which name you reserved a ticket earlier?

USER: My name in the  previous ticket is Michelle Garcia.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

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

USER: That's fine, anyway's thank you for searching.

ASSISTANT: My pleasure. Thank you for choosing us.