function navOn(element)
{

   if (!document.getElementById) return;

document.getElementById(element).style.backgroundImage = "url('images/nav_graphic_center_hover.jpg')";

}

function navOff(element)
{

   if (!document.getElementById) return;

document.getElementById(element).style.backgroundImage = "url('images/nav_graphic_center.jpg')";

}


function applyPageBorders(opacity)
{

   if (!document.getElementById) return;

var page_border_left = document.getElementById('page_border_left').style;
var page_border_right = document.getElementById('page_border_right').style;

   if (typeof page_border_left.filter != 'undefined')
   {
   opacity = opacity*10;

   page_border_left.backgroundImage = "url('images/shadow_left.gif')";
   page_border_right.backgroundImage = "url('images/shadow_right.gif')";
   page_border_left.filter = 'alpha(opacity=' + opacity + ')';
   page_border_right.filter = 'alpha(opacity=' + opacity + ')';
   }
   else if (typeof page_border_left.opacity != 'undefined')
   {
   opacity = opacity/10;

   page_border_left.backgroundImage = "url('images/shadow_left.gif')";
   page_border_right.backgroundImage = "url('images/shadow_right.gif')";
   page_border_left.opacity = opacity;
   page_border_right.opacity = opacity;
   }

}