isIE=document.all;
isNN=!document.all&&document.getElementById;
isN4=document.layers;

function trap() {
  if(document.images){
    for(i=0;i<document.images.length;i++) {
//      document.images[i].onmousedown = right;
//      document.images[i].onmouseup = right;
      document.images[i].oncontextmenu = right;
    }
  }
}

function right(e) {
  if (isNN) {
    if (e.which == 19||e.which == 2||e.which == 94) {
      return false;
    }else{
      return true;
    }
  }
  if (isIE) {
    if (event.button==2||event.button==0) {
      return false;
    }else{
      return true;
    }
  } 
  return false;
}