function checkImage(e) {
if (document.all) {
    if ("IMG" == event.srcElement.tagName) return false;
  } else if (document.getElementById) {
    if ("IMG" == e.target.tagName) return false;
  }
}

function filterSelectability(){
  var inputName=event.srcElement.name;
  if (typeof(inputName) == "undefined"){
    return false;
  }
  if ('INPUT'== event.srcElement.tagName) {
    return true;
  } else {
    return false;
  }
}
if(document.layers) {
  
  window.captureEvents(Event.MOUSEDOWN);
  window.onmousedown = function(e) {
    if(e.target==document || e.which == 3) return false;
  }
} else if (document.all) {
  
  document.oncontextmenu = checkImage;
  document.onselectstart= filterSelectability;
}
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