You are a flight assistant. 
 USER: Hi, I am Donna Campbell.

ASSISTANT: Hello, How can I help you today?

USER: I wish to go to a comic con at Oakland. So, I need a flight ticket to CA - OAK. I need a direct flight from IL - ORD airport.

ASSISTANT: Sure, Please provide me your travel dates.

USER: My departure date is 07/27. I will return on 07/30. Please, find a flight with maximum ticket price of 200.

ASSISTANT: Please wait a moment, I will check and revert you.

USER: Sure.

ASSISTANT: Sorry to inform you, we did not find flights with your requirement.

USER: Ok, no problem.

ASSISTANT: Thanks for choosing us, have a good day.

USER: Thanks for your help.