.hidden { visibility:hidden; font-size:0; }

#header { background-image:url(/exhibits/charters/images/nav/top_architecture_bg.jpg); background-position:50% 0; background-repeat:no-repeat; margin-bottom:15px; }

#charterslogo { display:block; margin:0; padding:17px 0 0 0; width:770px; height:41px; }
#charterslogo img { border:none; }

#mainNav { position:relative; width:770; height:96px; }
#mainNavHome { position:relative; width:770; height:96px; background-image:url(/exhibits/charters/images/main_page/header_bottom.gif); background-position:bottom left; background-repeat:no-repeat; }

.mainNav1 { display:block; position:absolute; left:0; top:0; width:154px; height:44px; background-image:url(/exhibits/charters/images/nav/btn_main_01_off.gif); background-repeat:no-repeat; }
.mainNav1:hover, 
.mainNav1on { display:block; position:absolute; left:0; top:0; width:154px; height:44px; background-image:url(/exhibits/charters/images/nav/btn_main_01_on.gif); background-repeat:no-repeat; }

.mainNav2 { display:block; position:absolute; left:154px; top:0; width:154px; height:44px; background-image:url(/exhibits/charters/images/nav/btn_main_02_off.gif); background-repeat:no-repeat; }
.mainNav2on, .mainNav2:hover { display:block; position:absolute; left:154px; top:0; width:154px; height:44px; background-image:url(/exhibits/charters/images/nav/btn_main_02_on.gif); background-repeat:no-repeat; }

.mainNav3 { display:block; position:absolute; left:308px; top:0; width:154px; height:44px; background-image:url(/exhibits/charters/images/nav/btn_main_03_off.gif); background-repeat:no-repeat; }
.mainNav3on, 
.mainNav3:hover { display:block; position:absolute; left:308px; top:0; width:154px; height:44px; background-image:url(/exhibits/charters/images/nav/btn_main_03_on.gif); background-repeat:no-repeat; }

.mainNav4 { display:block; position:absolute; left:462px; top:0; width:154px; height:44px; background-image:url(/exhibits/charters/images/nav/btn_main_04_off.gif); background-repeat:no-repeat; }
.mainNav4on, 
.mainNav4:hover { display:block; position:absolute; left:462px; top:0; width:154px; height:44px; background-image:url(/exhibits/charters/images/nav/btn_main_04_on.gif); background-repeat:no-repeat; }

.mainNav5 { display:block; position:absolute; left:616px; top:0; width:154px; height:44px; background-image:url(/exhibits/charters/images/nav/btn_main_05_off.gif); background-repeat:no-repeat; }
.mainNav5on, 
.mainNav5:hover { display:block; position:absolute; left:616px; top:0; width:154px; height:44px; background-image:url(/exhibits/charters/images/nav/btn_main_05_on.gif); background-repeat:no-repeat; }