header{
    position: fixed !important;  
    position: absolute;  
    top: 0;  
    left: 0;
    width: 100%;
    height: 100px;
    margin: 0 auto;
    background: #fff;
    z-index: 10;

}

header a:hover{
	filter:alpha(opacity=90);
	-moz-opacity: 0.9;
	opacity: 0.9;
	}