// Note: Opera and WebTV spoof Navigator.  We do strict client detection.
// If you want to allow spoofing, take out the tests for opera and webtv.
var is_nav     = ((agt.indexOf('mozilla')!=-1) && (agt.indexOf('spoofer')==-1)
                 && (agt.indexOf('compatible') == -1) && (agt.indexOf('opera')==-1)
                 && (agt.indexOf('webtv')==-1) && (agt.indexOf('hotjava')==-1));
var is_nav2    = (is_nav && (is_major == 2));
var is_nav3    = (is_nav && (is_major == 3));
var is_nav4    = (is_nav && (is_major == 4));
var is_nav4up  = (is_nav && (is_major >= 4));
var is_navonly = (is_nav && ((agt.indexOf(";nav") != -1) || (agt.indexOf("; nav") != -1)) );
var is_nav6    = (is_nav && (is_major == 5));
var is_nav6up  = (is_nav && (is_major >= 5));
var is_gecko   = (agt.indexOf('gecko') != -1);