css遮罩代码（已验证）

<span style="color: #000000;">#mask
{
    background-color: rgb(0, 0, 0);
    display:none;
    opacity: 0.0; /* Safari, Opera */
    -moz-opacity:0.0; /* FireFox */
    filter: alpha(opacity=0); /* IE */
    z-index: 100;
    height: 100%;
    width: 100%;
    background-repeat:repeat;
    position:fixed;
    top: 0px;
    left: 0px;
}</span>

<span style="color: #0000ff;"><span style="color: #800000;">div </span><span style="color: #ff0000;">id</span><span style="color: #0000ff;">="mask"</span><span style="color: #ff0000;"> class</span><span style="color: #0000ff;">="mask"</span><span style="color: #0000ff;">></span><span style="color: #800000;">div</span><span style="color: #0000ff;">></span></span>