var message="Opcion deshabilitada"; 
function click(e) {
if (document.all) {
if (event.button == 2) {
alert(message);
return false;}}
if (document.layers) {
if (e.which == 3) {
alert(message);
return false;}}}
if (document.layers) {
document.captureEvents(Event.MOUSEDOWN);}
document.onmousedown=click;

document.onselectstart=function(){return false}
document.ondragstart=function(){return false}


ie4 = (document.all)? true:false
ns6 = ((!document.all) && (document.getElementById))? true:false


passport = ((ie4) || (ns6))? true:false


if(navigator.appVersion.indexOf("Konqueror") != -1) passport = false
else if(navigator.appVersion.indexOf("Opera") != -1) passport = false


function keyDown(cual) {
if (ie4) tecla=event.keyCode
else if (ns6) tecla=cual.which


if(tecla == 17) {
        alert("Tecla invalida");
        return false;
        //if(ns6) window.stop()
        }
}


if(ie4) document.onkeydown = keyDown
else document.onkeyup = keyDown