You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Dennis Baker.

ASSISTANT: How may I help you?

USER: I have to modify my trip dates in my previous ticket. Can you please help me in changing the ticket details?

ASSISTANT: Sure, I will help you out.

USER: Thank you.

ASSISTANT: Please wait for a while.

USER: Sure, I will wait for your reply.

ASSISTANT: Sorry, there are no reservations found.

USER: It's ok, thank you for the information.

ASSISTANT: Thank you for choosing us.