Nivo Slider hiding my CSS Menu

Seen that this question has been asked before, but I cannot get it working with the solutions given;

The site is http://digitalstr.com

I have changed the z-index on all of the menu to 99999, yet still it 开发者_JS百科is below.

<div id="slidercont"> 
<div id="slider"> 
        <img src="http://digitalstr.com/wp-content/uploads/2011/09/ibfconpromo.png" /> 
    <img src="http://digitalstr.com/wp-content/uploads/2011/09/irconspacepromo.png" />
</div> 

#access {
    background: #3b95bd; /* Show a solid color for older browsers */
    clear: both;
    display: block;
    float: left;
    margin: 0 auto 6px;
    width: 100%;
    z-index: 99999;
}
.menu {
    margin-top:-20px !important;
    z-index: 99999;
}
#access ul {
    font-size: 13px;
    list-style: none;
    margin: 0 0 0 -0.8125em;
    padding-left: 0;
    z-index: 99999;
}
#access li {
    float: left;
    position: relative;
    z-index: 99999;
}
#access a {
    color: #eee;
    display: block;
    line-height: 3.333em;
    padding: 0 1.2125em;
    text-decoration: none;
    z-index: 99999;
}
#access ul ul {
    -moz-box-shadow: 0 3px 3px rgba(0,0,0,0.2);
    -webkit-box-shadow: 0 3px 3px rgba(0,0,0,0.2);
    box-shadow: 0 3px 3px rgba(0,0,0,0.2);
    display: none;
    float: left;
    margin: 0;
    position: absolute;
    top: 3.333em;
    left: 0;
    width: 140px;
    z-index: 99999;
}
#access ul ul ul {
    left: 100%;
    top: 0;
    z-index: 99999;
}
#access ul ul a {
    background: #f9f9f9;
    border-bottom: 1px dotted #ddd;
    color: #444;
    font-size: 13px;
    font-weight: normal;
    height: auto;
    line-height: 1.4em;
    padding: 10px 10px;
    width: 120px;
    z-index: 99999;
}

z-index only works on positioned elements so try setting position:relative on everything with z-index.

Update: Try this:

#branding {
border-top: 2px solid #BBBBBB;
padding-bottom: 10px;
position: relative;
z-index: 2; // REMOVE THIS LINE
}

every element should set position:relative or position:absolute when use z-index

try to change your css file at http://digitalstr.com/wp-content/themes/twentyeleven/nivo-slider/nivo-slider.css

#slidercont { 
width: 929px;
margin: 0 auto;
height: 260px; 
z-index:10; 
position:relative ; //or  position:absolute
} 

it worked for me

.nivoSlider {
    position:relative;
    width:100%;
    height:auto;
    overflow: hidden;
    z-index:-50;
}