ajax异步通讯 遮罩滚动栏，防止并发及误操作

加入滚动栏的遮罩，滚动栏图片须要自己调整路径

function loading() {

    var divloading = "<div id="loadingdiv" style="100%;height:100%;position:absolute;margin:auto;display:table;padding:auto;background-color:#EBEBEB;opacity:0.7;filter:alpha(Opacity=70);z-index:100;"><div id="loadingdivcontent" style="100%;vertical-align:middle; display:table-cell;margin:auto;text-align:center;position:absolute;top:45%;"><img src="../images/refresh.gif"/></div></div>";
    //$("loadingdiv").css({ "z-index": "-10", "opacity": "0.5" });
    $("body").prepend(divloading);

}

关闭遮罩图

function loadClose() {
    $("#loadingdiv").remove();
}