var navImgLo = new Array();
var navImgHi = new Array();
var currentItem = 0;

for (i=1; i<8; i++) {
  key = "navitem"+i;
  navImgLo[key] = new Image;
  navImgLo[key].src = "fileadmin/navi/nav_"+i+"_l.gif";
  navImgHi[key] = new Image;
  navImgHi[key].src = "fileadmin/navi/nav_"+i+"_h.gif";
}

function navHi(itemid) {
  document.images[itemid].src = navImgHi[itemid].src;
  currentItem = itemid;
}

function navLo(itemid) {
  document.images[itemid].src = navImgLo[itemid].src;
}

function keepHi() {
  navHi(currentItem);
}

function pushLo() {
  navLo(currentItem);
}