Async Multiple AJAX requests without affecting the responses to the UI

Async Multiple AJAX requests without affecting the responses to the UI

Im trying to make a system where user selects the condition and clicks on generate report( these reports takes more then 10 minutes). Once the request is fired, and immediately another request is made, the UI freezes till the first request is fullfilled, how to over come the same in terms of the process of making the request does not freeze the UI.

note: - Making ASYNC=true calls via AJAX