if (/Firefox[\/\s](\d+\.\d+)/.test(navigator.userAgent))
{
	var ffversion = new Number(RegExp.$1);
	if (ffversion >= 3)
	{
		var s = document.createElement('script');
		s.type = 'text/javascript';
		s.src = '/js/ff3_specific.js';
		document.getElementsByTagName('head')[0].appendChild(s);
	}
	else if (ffversion >= 2)
	{
		alert("You're using FF 2.x");
	}
	else if (ffversion >= 1)
	{
		alert("You're using FF 1.x");
	}
}