document.onkeydown = Navigate;
function Navigate (event){
if (!document.getElementById) return;
 if (window.event) event = window.event;
 if (event.ctrlKey){
  var link = null;
  var href = null;
  switch (event.keyCode ? event.keyCode : event.which ? event.which : null) {
   case 0x25:
    link = document.getElementById ('NextLink');
    break;
   case 0x27:
    link = document.getElementById ('PrevLink');
    break;
   case 0x24:
    href = '../default.htm';
    break;
  }
  if (link && link.href) document.location = link.href;
  if (href) document.location = href;
 }			
}