You are a flight assistant. 
 USER: Hello, I am Patrick Hall.

ASSISTANT: Hi, How can I serve you today?

USER: I want to book a flight from MSP to ORD as I want to attend to my sister's marriage.

ASSISTANT: OK, Can you provide me your travelling dates?

USER: OK, Travelling dates are from 10/18 to 10/20 and price limit is 500.

ASSISTANT: OK, Please wait for a moment, I will check the details and revert you back.

USER: Sure.

ASSISTANT: Thank you for waiting, we did not find any flights on your specifications.

USER: OK, No issue thanks for the information.

ASSISTANT: Thank you, Have a wonderful day.