About the pop-up layer, black background_html/css_WEB-ITnose

.black_overlay{ display: block; position: absolute; top: 0%; left: 0%; width: 100%; height: 100%; background-color: black; z-index:9998; -moz-opacity : 0.8; opacity: 0.80; filter: alpha(opacity=80); }

This is a very common pop-up layer black background style on the Internet, but if the web page is very wide, very long, or has a width or length, Varies
width: 100%; cannot meet the requirements. For example, if the web page is very wide and the user drags the mouse to the right and a pop-up pops up, the pop-up only covers 100% of the web page on the left, while the newly dragged one on the right is not covered.

I don’t want to specify a large range like width: 99999px, because the length of the scroll bar will change, and the original web page is not that wide.

What I want to cover is a GridView. Can I specify its width according to the width of the div where the GridView is located?

Reply to discussion (solution)

document.getElementById('fade').style.height
= document.documentElement.clientHeight document.documentElement.scrollTop 'px' ;

var isStrict='CSS1Compat'==document.compatMode,el=isStrict?'documentElement':'body';var w=document[el].scrollWidth,h=document[el].scrollHeight;alert(w+'\n'+h);//w和h为你页面宽和高

This pops up from the background of ASP.NET, so I cannot perform such complex JavaScript calculations.

javascript popup layer