var nav_images = {
 'header_nav_main': {    'on'   : '/wp-content/themes/vdg/images/navImages/vdg_nav_main_on.png',
                         'over' : '/wp-content/themes/vdg/images/navImages/vdg_nav_main_over.png',
                         'off'  : '/wp-content/themes/vdg/images/navImages/vdg_nav_main_off.png' },
 'header_nav_forum': {   'on'   : '/wp-content/themes/vdg/images/navImages/vdg_nav_forum_on.png',
                         'over' : '/wp-content/themes/vdg/images/navImages/vdg_nav_forum_over.png',
                         'off'  : '/wp-content/themes/vdg/images/navImages/vdg_nav_forum_off.png' },
 'header_nav_gallery': { 'on'   : '/wp-content/themes/vdg/images/navImages/vdg_nav_gallery_on.png',
                         'over' : '/wp-content/themes/vdg/images/navImages/vdg_nav_gallery_over.png',
                         'off'  : '/wp-content/themes/vdg/images/navImages/vdg_nav_gallery_off.png' }
};
for (nav_image in nav_images) {
  for (nav_state in nav_image) {
    var img = new Image();
    img.src = nav_images[nav_image][nav_state];
  }
}

// this highlights the image
function highlight(img,state) {
  eval("document.getElementById('" + img + "_img').src = nav_images['" + img + "']['" + state + "']");
}

// this lifts and drops the image
function lifter(nav,state) {

  var navdiv = eval("document.getElementById('" + nav + "').parentNode");
  var navdiv_curpos = parseInt( navdiv.style.top );
  var dist = 8;
  var intr = 15;
  var i = 0;
  var cur = false;

  if (state == 'over') {
    // go from 8 to 0
    cur = 8;
    var direction = 'dec';
  } else if (state == 'off') {
    // go from 0 to 8
    cur = 0;
    var direction = 'inc';
  }
  //if ( cur != navdiv_curpos ) return;
  var mover = function ()
  {
    cur = ( direction == 'dec' ) ? cur - 1 : cur + 1;
    navdiv.style.top = cur + 'px';
    i++;
    // if there's more to go, and we're not over or under the boundary...
    if (i <= dist && ( (direction == 'dec' && cur > 0) || (direction == 'inc' && cur < dist) )) { timer = setTimeout(mover, intr) };
  };
  mover();
}

function nav_init (cur_nav) {
  for ( nav in nav_images ) {
    if ( nav != cur_nav ) {
      var this_nav = nav;
      eval("nav_elm = document.getElementById('" + this_nav + "');");
      eval("nav_elm.onmouseover = function () { highlight('" + this_nav+ "','over'); lifter('" + this_nav + "','over'); };");
      eval("nav_elm.onmouseout  = function () { highlight('" + this_nav + "','off'); lifter('" + this_nav + "','off'); };");
    }
  }
}