Problema com menu css

Não consigo fazer com que a pagina selecionada fique marcada no menu.Fica sempre na Home, quando eu troco de pagina deveria ficar marcado no menu em qual está, mas fica sempre no menu.

/ Base Styles /

#cssmenu ul,

#cssmenu li,

#cssmenu a {

 list-style: none;

 margin: 0;

 padding: 0;

 border: 0;

 line-height: 1;

 font-family: 'Lato', sans-serif;

 

 

}

#cssmenu {

 border: 1px solid #133e40;

 -webkit-border-radius: 5px;

 -moz-border-radius: 5px;

 -ms-border-radius: 5px;

 -o-border-radius: 5px;

 border-radius: 5px;

 width: auto;

}

#cssmenu ul {

 zoom: 1;

 background: #6E8B3D;

 

 filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='@top-color', endColorstr='@bottom-color', GradientType=0);

 padding: 5px 10px;

 -webkit-border-radius: 5px;

 -moz-border-radius: 5px;

 -ms-border-radius: 5px;

 -o-border-radius: 5px;

 border-radius: 5px;

}

#cssmenu ul:before {

 content: '';

 display: block;

}

#cssmenu ul:after {

 content: '';

 display: table;

 clear: both;

}

#cssmenu li {

 float: left;

 margin: 0 5px 0 0;

 border: 1px solid transparent;

}

#cssmenu li a {

 -webkit-border-radius: 5px;

 -moz-border-radius: 5px;

 -ms-border-radius: 5px;

 -o-border-radius: 5px;

 border-radius: 5px;

 padding: 8px 15px 9px 15px;

 display: block;

 text-decoration: none;

 color: #ffffff;

 border: 1px solid transparent;

 font-size: 16px;

}

#cssmenu li.active {

 -webkit-border-radius: 5px;

 -moz-border-radius: 5px;

 -ms-border-radius: 5px;

 -o-border-radius: 5px;

 border-radius: 5px;

 border: 1px solid #36b0b6;

}

#cssmenu li.active a {

 -webkit-border-radius: 5px;

 -moz-border-radius: 5px;

 -ms-border-radius: 5px;

 -o-border-radius: 5px;

 border-radius: 5px;

 display: block;

 background: #A2B5CD;

 border: 1px solid #A2B5CD;

 -moz-box-shadow: inset 0 5px 10px #133e40;

 -webkit-box-shadow: inset 0 5px 10px #133e40;

 box-shadow: inset 0 5px 10px #133e40;

}

#cssmenu li:hover {

 -webkit-border-radius: 5px;

 -moz-border-radius: 5px;

 -ms-border-radius: 5px;

 -o-border-radius: 5px;

 border-radius: 5px;

 border: 1px solid #36b0b6;

}

#cssmenu li:hover a {

 -webkit-border-radius: 5px;

 -moz-border-radius: 5px;

 -ms-border-radius: 5px;

 -o-border-radius: 5px;

 border-radius: 5px;

 display: block;

 background: #A2B5CD;

 border: 1px solid #A2B5CD;

 -moz-box-shadow: inset 0 5px 10px #133e40;

 -webkit-box-shadow: inset 0 5px 10px #133e40;

 box-shadow: inset 0 5px 10px #133e40;

}