js遮罩效果

function ShowLoadingMaskLayer(text) {
    var htmlContent = '<div id="masklayer">' +
        '<div id="covered" style="position:fixed;_position:absolute;z-index:888;top:0px; left:0px;100%;height:100%;background-color:#696969;opacity:0.5;">' +
        '</div>' +
        '<div id="poplayer" style=" position:absolute;top:46%;left:46%;130px; height:42px;z-index:8888; background-color:#ffffff;border:3px solid #95B8E7;">' +
        '<img src="/Scripts/Projects/icons/ico_loading2.gif" style="position:absolute;top:10px;left:10px;22px;height:22px;"/>' +
        '<span style="position:absolute;top:15px;left:52px;" id="masklayertext">' + text + '...</span>' +
        '</div>' +
        '</div>';
    $("#masklayerDiv").html(htmlContent);
}

function CloseLoadingMaskLayer() {
    $("#masklayerDiv").html("");
}