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("[ Warning !!!, you can't use right click ]");
                return false;
        }
                return true;
         }

        document.onmousedown = right;
        document.onmouseup = right;