var message = 'Copyright © Escayola La Paloma, S.A. - Todos los derechos reservados.';

function clickIE4() {
    if (event.button == 2) {
        alert(message);
        return false;
    }
}

function clickNS4(e) {
    if (document.layers || document.getElementById && !document.all) {
        if (e.which == 2 || e.which == 3) {
            alert(message);
            return false;
        }
    }
}

if (document.layers) {
    document.captureEvents(Event.MOUSEDOWN);
    document.onmousedown = clickNS4;
}
else if (document.all && !document.getElementById) {
    document.onmousedown=clickIE4;
}

document.oncontextmenu = new Function("alert(message); return false");

<!--
IE4 = (document.all);
NS4 = (document.layers);
    
if (NS4) {
    document.captureEvents(Event.KEYPRESS);
}

document.onkeypress = doKey;
    
function doKey(e) {
    whichASC = (NS4) ? e.which : event.keyCode;
    whichKey = String.fromCharCode(whichASC).toLowerCase();
   
    switch (whichASC) {
        case 13:
            document.forms[0].submit();
            break;
        default:
            break;
    }
}
-->