function right(e) {
if (navigator.appName == 'Netscape' &&
(e.which == 3 || e.which == 2))
return false;
else if (navigator.appName == 'Microsoft Internet Explorer' &&
(event.button == 2 || event.button == 3)) {
alert("Copyright Esmeyer GmbH & Co. KG 1997-2009 ;-)");
return false;
}
return true;
}

document.onmousedown=right;
if (document.layers) window.captureEvents(Event.MOUSEDOWN);
window.onmousedown=right;

function check()
{
if(event.button == 2)
{
alert("Sie haben die rechte Maustaste gedrückt ! ;-)");
}
}