var IE;
var NN;

if(navigator.appName=="Microsoft Internet Explorer")
{
IE=true;
}

if(navigator.appName=="Netscape")
{
NN=true;
}

function right(click)
{
if(IE && (event.button==2 || event.button==3))
{
alert("The right click has been disabled here.");
return false;
}

if(NN && (click.which==2 || click.which==3))
{
alert("The right click has been disabled here.");
return false;
}

return false;
}
if (document.layers) window.captureEvents(Event.MOUSEDOWN);
if (document.layers) window.captureEvents(Event.MOUSEUP);
document.onmousedown=right;
document.onmouseup=right;
window.document.layers=right;