js遮罩层，锁屏

加载图片：

//锁屏
function lockWindow(message) {
    unlockWindow();
    if (message == null || message == '') {
        message = '正在加载，请稍候...';
    }
    var a = basePath + 'ecm-view/public/images/blue-loading.gif';
    var floatDiv = window.document.createElement("div");
    var width = (window.top.document.documentElement).scrollLeft + (window.top.document.documentElement).scrollWidth;
    var height = (window.top.document.documentElement).scrollTop + (window.top.document.documentElement).scrollHeight;
    floatDiv.id = "floatDiv";
    var styleStr = "top:0;left:0px;position:absolute;background:#E7EFEF;width:" + width + "px;height:" + height + "px;filter: alpha(opacity=85);-moz-opacity: 0.85;opacity: 0.85;z-index:99998;";
    floatDiv.style.cssText = styleStr;
    window.top.document.body.appendChild(floatDiv);
    var floatDivTop = (floatDiv.style.top).split('p');
    var floatDivHight = Number(floatDivTop[0]);
    var newTop = (floatDivHight + Number(height)) * 0.4;
    var msgWindow = window.top.document.createElement("div");
    msgWindow.id = "msgWindow";
    msgWindow.className = "msgWindow";
    msgWindow.innerHTML = "<div style=position:absolute;top:20%;left:10%;><img src='" + a + "' width='32px' height='32px'/></div><div style='padding:20px;text-align:right'>" + message + "</div>";
    var styleStr2 = "left:40%;top:" + newTop + "px;position:absolute;width:200px;background-color:white;border: 1px solid #ccc;z-index:99999;";
    msgWindow.style.cssText = styleStr2;
    window.top.document.body.appendChild(msgWindow);
};
//解屏
function unlockWindow() {
    var msgWindow = window.top.document.getElementById("msgWindow");
    var floatDiv = window.top.document.getElementById("floatDiv");
    if (msgWindow != undefined && msgWindow != null) {
        window.top.document.body.removeChild(msgWindow);
    }
    if (floatDiv != undefined && floatDiv != null) {
        window.top.document.body.removeChild(floatDiv);
    }
};