<https://w3schools.invisionzone.com/topic/53171-problem-with-blur/#comment-293022>
<http://schema.org/text>
"yes, but as you can see they wrote in the ref that it support in all broswers, so its wird :| \n  \nanyway, can you answer mi first que? i want to open popup, but that he will be in the background, i mean that the window will open, but you dont see him because he will be behind the opener (main) window, i see it in some site but i dont know how to do this... \n"
<https://w3schools.invisionzone.com/topic/53171-problem-with-blur/?tab=comments#comment-293006>