var is_nav, is_nav4,  is_nav4up, is_nav6, is_nav60_61, is_nav6up, is_gecko, is_mac;
var is_ie, is_ie3, is_ie4, is_ie4up, is_ie5up, is_ie6;
var is_opera, is_opera2, is_opera3, is_opera4, is_opera5, is_opera6, is_opera6up;
var is_notsupported=true;

function BrowserDetect(){
	//Browser detection, we check if the browser is supported
	//dans le cas contraire la variable is_notsupported est créée

	var agt=navigator.userAgent.toLowerCase();
	var is_major = parseInt(navigator.appVersion);
	var is_minor = parseFloat(navigator.appVersion);

	// Netscape
	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));
	is_nav4 = (is_nav && (is_major == 4));
	is_nav4up = (is_nav && (is_major >= 4));
	is_nav6 = (is_nav && (is_major == 5));
	is_nav60_61 = is_nav6 && (agt.indexOf("netscape6/6.0")>=0 || agt.indexOf("netscape6/6.1")>=0);
	is_nav6up = (is_nav && (is_major >= 5));
	is_gecko = (agt.indexOf('gecko') != -1);

	// Internet Explorer
	is_ie     = ((agt.indexOf("msie") != -1) && (agt.indexOf("opera") == -1));
	is_ie3    = (is_ie && (is_major < 4));
	is_ie4    = (is_ie && (is_major == 4) && (agt.indexOf("msie 4")!=-1) );
	is_ie4up  = (is_ie && (is_major >= 4));
	is_ie5up  = (is_ie && !is_ie3 && !is_ie4);
	is_ie6    = (is_ie && (is_major == 4) && (agt.indexOf("msie 6.")!=-1) );

	// Opera
	is_opera = (agt.indexOf("opera") != -1);
	is_opera2 = (agt.indexOf("opera 2") != -1 || agt.indexOf("opera/2") != -1);
	is_opera3 = (agt.indexOf("opera 3") != -1 || agt.indexOf("opera/3") != -1);
	is_opera4 = (agt.indexOf("opera 4") != -1 || agt.indexOf("opera/4") != -1);
	is_opera5 = (agt.indexOf("opera 5") != -1 || agt.indexOf("opera/5") != -1);
	is_opera6 = (agt.indexOf("opera 6") != -1 || agt.indexOf("opera/6") != -1);
	is_opera6up = (is_opera && !is_opera2 && !is_opera3 && !is_opera4 && !is_opera5);

	//Plateforme mac
	is_mac    = (agt.indexOf("mac")!=-1);

	//Otherwise it's not supported
	is_notsupported = !is_nav4 && !is_nav6up && !is_gecko && !is_ie4up && !is_opera6up;
}