function changeOn(id) {
  identity=document.getElementById(id);
  if (identity.className == 'headerNav') identity.className = 'headerNavOn';
}

function changeOut(id) {
  identity=document.getElementById(id);
  if (identity.className == 'headerNavOn') identity.className = 'headerNav';
}

function changeCorner(status) {
 if (status=='on') {
   document.leftCorner.src='images/header_r2_c2_green.gif';
 } else if (status=='off') {
   document.leftCorner.src='images/header_r2_c2.gif';
 }
}