darken Website (JS/AJAX) when order is sent

Hi!

Is it possible to access the JS that darkens the Website (e.g. Add to Cart-Button --> Window with Buttons appears, background is gray) for another button event. I want this for the button when an order is sent, has to be in the "checkout / step.php". At the moment all I reached was the button to be inactive with document.getElementById(\'hikashop_checkout_next_button\').disabled=true as onClick-Event.

Reason for this is that the server needs sometimes more than a second to redirect the user to the "Thanks for purchase"-site (you see the loading symbol in the browser) and maybe an impatient customer will click somewhere else and an error occurs. So I want to display somthing that clearly says "Server is working, please wait a second" (some animated bar or circle, like you have on nearly every Website today).

I thought this kind of pop-up could do the job, but maybe there is a simpler way to implement a kind of barrier for the customer.

kind regards!