// convert all characters to lowercase to simplify testing
var agt = navigator.userAgent.toLowerCase();

// *** BROWSER VERSION ***
// Note: On IE5, these return 4, so use is_ie5up to detect IE5.
var is_major = parseInt(navigator.appVersion);
var is_minor = parseFloat(navigator.appVersion);

// 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));
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_nav5 = (is_nav && (is_major == 5));
var is_nav5up = (is_nav && (is_major >= 5));

var is_ie   = (agt.indexOf("msie") != -1);
var is_ie3  = (is_ie && (is_major < 4));
var is_ie4  = (is_ie && (is_major == 4) && (agt.indexOf("msie 5.0")==-1) );
var is_ie4up  = (is_ie  && (is_major >= 4));
var is_ie5  = (is_ie && (is_major == 4) && (agt.indexOf("msie 5.0")!=-1) );
var is_ie5up  = (is_ie  && !is_ie3 && !is_ie4);

// KNOWN BUG: On AOL4, returns false if IE3 is embedded browser
// or if this is the first browser window opened.  Thus the
// variables is_aol, is_aol3, and is_aol4 aren't 100% reliable.

var is_aol   = (agt.indexOf("aol") != -1);
var is_aol3  = (is_aol && is_ie3);
var is_aol4  = (is_aol && is_ie4);

var is_opera = (agt.indexOf("opera") != -1);
var is_webtv = (agt.indexOf("webtv") != -1);

// *** JAVASCRIPT VERSION CHECK ***
var is_js;
if (is_nav2 || is_ie3) is_js = 1.0
else if (is_nav3 || is_opera) is_js = 1.1
else if ((is_nav4 && (is_minor <= 4.05)) || is_ie4) is_js = 1.2
else if ((is_nav4 && (is_minor > 4.05)) || is_ie5) is_js = 1.3
else if (is_nav5) is_js = 1.4
// NOTE: In the future, update this code when newer versions of JS
// are released. For now, we try to provide some upward compatibility
// so that future versions of Nav and IE will show they are at
// *least* JS 1.x capable. Always check for JS version compatibility
// with > or >=.

else if (is_nav && (is_major > 5)) is_js = 1.4
else if (is_ie && (is_major > 5)) is_js = 1.3
// HACK: no idea for other browsers; always check for JS version with > or >=

else is_js = 0.0;

//
// ************** MESSAGE D'AVERTISSEMENT **************
//

if (is_nav4) {
  alert("Vous utilisez Nescape 4. Ce navigateur ne permet pas de consulter ce site dans de bonnes conditions.\n\n "+
        "Veuillez installer un navigateur plus récent (version 5 minimum).");
}