表单提交加遮罩层和防重复提交

遮罩层：

css里加

.loadingWrap{
    position:fixed;
    top:0;
    left:0;
    width:100%;
    height:100%;
    z-index:300;
    background-image:url(../img/loading2.gif);
    background-repeat:no-repeat;
    background-position:center center;
    background-color:#000;
    background-color:rgba(234, 229, 229, 0.5);
    filter:alpha(opacity=50);
}

js

$('<div class="loadingWrap"></div>').appendTo("body");

$(".loadingWrap").remove();    

防重复提交：