ul#nav_main {
	list-style-type: none;
	position: relative;
	left: 0;
	width: 651px;
	height: 38px;
	margin: 0;
	padding: 0;
	text-align: center;
	overflow: hidden;
}


li#nm_1 {
	position: absolute;
	top: 0px;
	left: 0px;
	width: 124px;
	height: 38px;
	text-align: center;
	background-image: url(../images/nav/nav01_web-off.png);
	background-repeat: no-repeat;
}
li#nm_2 {
	position: absolute;
	top: 0px;
	left: 124px;
	width: 198px;
	height: 38px;
	background-color: #FFFFFF;
	text-align: center;
	background-image: url(../images/nav/nav02_graphics-off.png);
	background-repeat: no-repeat;
}

li#nm_3 {
	position: absolute;
	top: 0px;
	left: 322px;
	width: 189px;
	height: 38px;
	background-color: #FFFFFF;
	text-align: center;
	background-image: url(../images/nav/nav03_services-off.png);
	background-repeat: no-repeat;
}

li#nm_4 {
	position: absolute;
	top: 0px;
	left: 511px;
	width: 140px;
	height: 38px;
	background-color: #FFFFFF;
	text-align: center;
	background-image: url(../images/nav/nav04_theory-off.png);
	background-repeat: no-repeat;
}


ul#nav_main a {display: block;
width: 651px;
height: 38px;
text-indent: -9999px;
text-decoration: none;
overflow: hidden; 
}




#web li#nm_1 a {
	background-image: url(../images/nav/nav01_web-on.png);
	background-repeat: no-repeat;
}
#graphics li#nm_2 a {
	background-image: url(../images/nav/nav02_graphics-on.png);
	background-repeat: no-repeat;
}
#services li#nm_3 a {
	background-image: url(../images/nav/nav03_services-on.png);
	background-repeat: no-repeat;
}
#theory li#nm_4 a {
	background-image: url(../images/nav/nav04_theory-on.png);
	background-repeat: no-repeat;
}






li#nm_1 a:hover {
	background-image: url(../images/nav/nav01_web-on.png);
	background-repeat: no-repeat;
}
li#nm_2 a:hover {
	background-image: url(../images/nav/nav02_graphics-on.png);
	background-repeat: no-repeat;
}
li#nm_3 a:hover {
	background-image: url(../images/nav/nav03_services-on.png);
	background-repeat: no-repeat;
}
li#nm_4 a:hover {
	background-image: url(../images/nav/nav04_theory-on.png);
	background-repeat: no-repeat;
}