让createElement创建的div层，始终在屏幕的中央，位置怎么控制啊！

[gzw323]

function CreateWaitElement()
{
var elem = document.getElementById('__AjaxCall_Wait');
if (!elem)
{
elem = document.createElement("div");
elem.id = '__AjaxCall_Wait';
elem.style.position = 'absolute';
//
elem.style.height = 25;
elem.style.width = 120;
elem.border = "1px";
elem.style.fontSize = "18px";
//elem.style.align="center";
elem.style.borderColor = "#990000";
elem.style.borderWidth = "0";
elem.style.borderStyle="solid";
elem.style.backgroundColor = "#990000";
elem.style.color = "#FFFFFF";
elem.innerHTML = "Load Date...";
alert(screen.availWidth-elem.style.pixelWidth);
alert(screen.availHeight-elem.style.pixelHeight);

//alert(elem.style.pixelLeft=(screen.availWidth-elem.style.pixelWidth)/2);
//alert(elem.style.pixelTop=(screen.availHeight-elem.style.pixelHeight)/2);
elem.style.visibility = 'hidden';
document.body.insertBefore(elem, document.body.firstChild);
}
waitElement = elem;
}


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下面的2行代码可以正确获得当前窗口的高度和宽度
alert(screen.availWidth-elem.style.pixelWidth);
alert(screen.availHeight-elem.style.pixelHeight);
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下面的代码用来设置层的左边和上边的高度，把高度和宽度除2，使div层始终在窗口的中央
elem.style.pixelLeft=(screen.availWidth-elem.style.pixelWidth)/2;
elem.style.pixelTop=(screen.availHeight-elem.style.pixelHeight)/2;

可实际执行结果是：
层横向始终在中央，但是top高度确始终在窗口的顶层，



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想问一下高手们，层的那个属性是控制，层位置的！～

我已经整了一周了

[pwl2014]

function CreateWaitElement()
{
var elem = document.getElementById("__AjaxCall_Wait");
if (!elem)
{
elem = document.createElement("div");
elem.id = '__AjaxCall_Wait';
elem.style.position = 'absolute';
//
elem.style.height = 25;
elem.style.width = 120;
elem.border = "1px";
elem.style.fontSize = "18px";
//elem.style.align="center";
elem.style.borderColor = "#990000";
elem.style.borderWidth = "0";
elem.style.borderStyle="solid";
elem.style.backgroundColor = "#990000";
elem.style.color = "#FFFFFF";
elem.innerHTML = "Load Date...";
alert(screen.availWidth-elem.style.pixelWidth);
alert(screen.availHeight-elem.style.pixelHeight);
elem.style.pixelLeft=(screen.availWidth-elem.style.pixelWidth)/2;
elem.style.pixelTop=(screen.availHeight-elem.style.pixelHeight)/2;
//alert(elem.style.pixelLeft=(screen.availWidth-elem.style.pixelWidth)/2);
//alert(elem.style.pixelTop=(screen.availHeight-elem.style.pixelHeight)/2);
//elem.style.visibility = 'hidden';
document.body.insertBefore(elem, document.body.firstChild);
}
waitElement = elem;
}
试了一下，没出现你说的问题。

[Student02370236]

DIV的STYLE属性中的LEFT和TOP就是控制层的位置的..

[gzw323]

这是MagicAjax控件里面的一个js文件，我也测了一下，在单独做成文件，测试可以，但是放到MagicAjax文件里面执行的时候就是不能居中！