Javascript 遮罩层和加载成效

//loading
function showLoad(tipInfo) {
    var iWidth = 120;     //弹出窗口的宽度;
    var iHeight = 0;    //弹出窗口的高度;
    var scrolltop = 0;
    var scrollleft = 0;
    var cheight = 0;
    var cwidth = 0;
    var eTip = document.createElement('div');
    eTip.setAttribute('id', 'tipDiv');
    eTip.style.position = 'absolute';
    eTip.style.display = 'none';
    eTip.style.border = 'solid 0px #D1D1D1';
    eTip.style.backgroundColor = '#4B981D';
    eTip.style.padding = '5px 15px';

    if(document.body.scrollTop){//这是一个js的兼容
        scrollleft=document.body.scrollLeft;
        scrolltop=document.body.scrollTop;
        cheight=document.body.clientHeight;
        cwidth=document.body.clientWidth;
    }
    else{
        scrollleft=document.documentElement.scrollLeft;
        scrolltop=document.documentElement.scrollTop;
        cheight=document.documentElement.clientHeight;
        cwidth=document.documentElement.clientWidth;
    }
    iHeight = eTip.offsetHeight;
    var v_left=(cwidth-iWidth)/2 + scrollleft; //
    var v_top=(cheight-iHeight)/2+ scrolltop;
    eTip.style.left = v_left + 'px';
    eTip.style.top = v_top + 'px';

    eTip.innerHTML = '<img src=\'Images/loading.gif\' style=\'float:left;\' />  <span style=\'color:#ffffff; font-size:12px\'>' + tipInfo + '</span>';
    try {
        document.body.appendChild(eTip);
    } catch (e) { }
    $("#tipDiv").css("float", "right");
    $("#tipDiv").css("z-index", "99");
    $('#tipDiv').show();
    ShowMark();
}

function closeLoad() {
    $('#tipDiv').hide();
    HideMark();
}


//显示蒙灰层
function ShowMark() {
    var xp_mark = document.getElementById("xp_mark");
    if (xp_mark != null) {
        //设置DIV
        xp_mark.style.left = 0 + "px";
        xp_mark.style.top = 0 + "px";
        xp_mark.style.position = "absolute";
        xp_mark.style.backgroundColor = "#000";
        xp_mark.style.zIndex = "1";
        if (document.all) {
            xp_mark.style.filter = "alpha(opacity=50)";
            var Ie_ver = navigator["appVersion"].substr(22, 1);
            if (Ie_ver == 6 || Ie_ver == 5) { hideSelectBoxes(); }
        }
        else { xp_mark.style.opacity = "0.5"; }
        xp_mark.style.width = "100%";
        xp_mark.style.height = "100%";
        xp_mark.style.display = "block";
    }
    else {
        //页面添加div explainDiv,注意必须是紧跟body 内的第一个元素.否则IE6不正常.
        $("body").prepend("<div id='xp_mark' style='display:none;'></div>");
        ShowMark(); //继续回调自己
    }
}

//隐藏蒙灰层
function HideMark() {
    var xp_mark = document.getElementById("xp_mark");
    xp_mark.style.display = "none";
    var Ie_ver = navigator["appVersion"].substr(22, 1);
    if (Ie_ver == 6 || Ie_ver == 5) { showSelectBoxes(); }
}