今天做项目需要用的一个div居中，下面一个模态层的问题，我写了个代码，大概分离出来如下。
<html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title></title> <style type="text/css"> div { width: 200px; height: 300px; background: red; border: 1px solid black; } </style> </head> <body> <div> </div> <div> </div> <div id="d" style="position: absolute; width: 200px; height: 300px;"> </div> <script type="text/javascript"> var pageWidth = 0; var pageHeight = 0; var left = "0px"; var top = "0px"; var divWidth = 0; var divHeight = 0; var d = document.getElementById("d"); if (d) { // divWidth = (d.style.width.toString()).replace("px", ""); // divHeight = (d.style.height.toString()).replace("px", ""); divWidth = parseInt(d.style.width.toString()); divHeight = parseInt(d.style.height.toString()); } if (document.compatMode == "CSS1Compat") { pageWidth = parseInt(document.documentElement.clientWidth); pageHeight = parseInt(document.documentElement.clientHeight); } else { pageWidth = parseInt(document.body.clientWidth); pageHeight = parseInt(document.body.clientHeight); } left = ((pageWidth - divWidth) / 2).toString() + "px"; top = ((pageHeight - divHeight) / 2).toString()+"px"; d.style.left = left d.style.top = ((pageHeight - divHeight) / 2).toString() + "px";//goog浏览器不得行???? d.innerHTML = "pageWidth:" + pageWidth + "<br/> pageHeight:" + pageHeight + "<br/> divWidth:" + divWidth + " <br/>divHeight:" + divHeight + " <br/>left:" + left + " <br/>top:" + top; </script> </body> </html> d.style.top = ((pageHeight - divHeight) / 2).toString() + "px";//goog浏览器不得行????
请注意这段代码，这个代码在IE，火狐，google浏览器下都没有问题，但是将这句改成
d.style.top = top；
google就错了。不知道什么原因？求解答。
