.preload1 {background: url(../imagenes/menu_horizontal/three_1.gif);}
.preload2 {background: url(../imagenes/menu_horizontal/three_1a.gif);}

#nav {padding:0; margin:auto; width:990px; list-style:none; height:38px; background:url(../imagenes/menu_horizontal/three_0.gif) repeat-x; position:relative; z-index:500;}
#nav li.top {display:block; float:left; height:38px;}
#nav li a.top_link {display:block; float:left; height:35px; line-height:33px; color:white; text-decoration:none; font-size:11px; font-weight:bold; padding:0 0 0 12px; cursor:pointer;background: url(../imagenes/menu_horizontal/three_0.gif);}
#nav li a.top_link span {float:left; display:block; padding:0 24px 0 12px; height:35px; background: url(../imagenes/menu_horizontal/three_0.gif) right top no-repeat;}
#nav li a.top_link span.down {float:left; display:block; padding:0 24px 0 12px; height:35px; background: url(../imagenes/menu_horizontal/three_0a.gif) no-repeat right top;}

#nav li:hover a.top_link {color:#fff; background: url(../imagenes/menu_horizontal/three_1.gif) no-repeat;}
#nav li:hover a.top_link span {background:url(../imagenes/menu_horizontal/three_1.gif) no-repeat right top;}
#nav li:hover a.top_link span.down {background:url(../imagenes/menu_horizontal/three_1a.gif) no-repeat right top;}

/* Default list styling */