Native js pop up layer and the window within it is centered
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><HTML><HEAD><TITLE> New Document </TITLE><meta charset="UTF-8"><meta http-equiv="Content-Type" content="text/html; charset=utf-8"/><META NAME="Author" CONTENT=""><META NAME="Keywords" CONTENT=""><META NAME="Description" CONTENT=""><style type="text/css">*{padding:0px;margin:0px;}#Idiv{width:900px;height:auto;position:absolute;z-index:1000;border:2px solid #ffffff;background:#ffffff;}</style></HEAD><body><div id="Idiv" style="display:none;"><a href="javascript:void(0)" onclick="closeDiv()"> Click close layer </a><br/>document.documentElement The difference between <br/>document.documentElement The difference between</div><div><a href="javascript:void(0)" id="show" onclick="show()"> Click open pop-up layer! </div></body><script langue="javascript">function show(){var Idiv=document.getElementById("Idiv");Idiv.style.display="block";//The following sections center the pop-up layerIdiv.style.left=(document.documentElement.clientWidth-Idiv.clientWidth)/2+document.documentElement.scrollLeft+"px";//alert(document.body.scrollTop)var aa_scrollTop = document.documentElement.scrollTop || window.pageYOffset || document.body.scrollTop;Idiv.style.top=(document.documentElement.clientHeight-Idiv.clientHeight)/2+aa_scrollTop+"px";// There is a problem here, pop layer left and right center, but the height is not center, show in the upper part, resulting in a // Part invisible , So I'm going to add it down here for now margin-top//The following sections make the entire page unclickablevar procbg = document.createElement("div"); //First, create a divprocbg.setAttribute("id","mybg"); //Define the id of the divprocbg.style.background ="#000000";procbg.style.width ="100%";procbg.style.height ="100%";procbg.style.position ="fixed";procbg.style.top ="0";procbg.style.left ="0";procbg.style.zIndex ="500";procbg.style.opacity ="0.6";procbg.style.filter ="Alpha(opacity=70)";//Cancel scroll bardocument.body.appendChild(procbg);document.body.style.overflow ="auto";//The following section implements the drag and drop effect of the pop-up layer (if you want the div inside the pop-up layer to move, just log off and remove the following)/*var posX;var posY;Idiv.onmousedown=function(e){if(!e) e = window.event; //IEposX = e.clientX - parseInt(Idiv.style.left);posY = e.clientY - parseInt(Idiv.style.top);document.onmousemove = mousemove;}document.onmouseup =function(){document.onmousemove =null;}function mousemove(ev){if(ev==null) ev = window.event;//IEIdiv.style.left = (ev.clientX - posX) +"px";Idiv.style.top = (ev.clientY - posY) +"px";}*/}function closeDiv() //Close the ejection layer{var Idiv=document.getElementById("Idiv");var mybg = document.getElementById("mybg");document.body.removeChild(mybg);Idiv.style.display="none";document.body.style.overflow ="auto";//Restore the page scroll bar//document.getElementById("mybg").style.display="none";}</script></HTML>//Change the above pop-up layer to do its own loading with a loading function. Determine whether the page is loaded, and then hide the loading. GIF<!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml"><head><title>New Document </title><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /></head><body onload="subSomething()"></body><script type="text/ecmascript">function show(addressImg, img_w, img_h) {//Get the page heightvar h = (document.documentElement.scrollHeight > document.documentElement.clientHeight) ? document.documentElement.scrollHeight : document.documentElement.clientHeight;//Get the page widthvar w = (document.documentElement.scrollWidth > document.documentElement.clientWidth) ? document.documentElement.scrollWidth : document.documentElement.scrollWidth;var procbg = document.createElement("div"); //First, create a divprocbg.setAttribute("id", "mybg"); //Define the id of the divprocbg.style.background = "#555";procbg.style.width = "100%";procbg.style.height = "100%";procbg.style.position = "fixed";procbg.style.top = "0";procbg.style.left = "0";procbg.style.zIndex = "500";procbg.style.opacity = "0.6";procbg.style.filter = "Alpha(opacity=70)";//Cancel scroll bardocument.body.appendChild(procbg);document.body.style.overflow = "auto";var pimg = document.createElement("img"); //Create an imgpimg.setAttribute("id", "bg_img"); //Define the id of the divpimg.setAttribute("src", addressImg); //Define the id of the divvar img_w = (w - img_w) / 2;var img_h = (h - img_h) / 2;pimg.style.top = img_h + "px";pimg.style.left = img_w + "px";pimg.style.position = "fixed";pimg.style.opacity = "0.9";document.getElementById("mybg").appendChild(pimg);}function closeDiv() //Close the ejection layer{var mybg = document.getElementById("mybg");document.body.removeChild(mybg);document.body.style.overflow = "auto";//Restore the page scroll bar//document.getElementById("mybg").style.display="none";}show('loading/loading3.gif', '100', '100');document.onreadystatechange = subSomething;//Execute this method when the page load state changes.function subSomething() {if (document.readyState == "complete") { //Enters when the page is fully loadedcloseDiv();}}</script></html>