// JavaScript Document

<!-- script pour détecter le naviguateur, sa version et la plateforme -->
<!-- source : www.quirksmode.org -->
var BrowserDetect = {
	init: function () {
		this.browser = this.searchString(this.dataBrowser) || "Naviguateur inconnu";
		this.version = this.searchVersion(navigator.userAgent)
			|| this.searchVersion(navigator.appVersion)
			|| "version inconnue";
		this.OS = this.searchString(this.dataOS) || "système inconnu";
	},
	searchString: function (data) {
		for (var i=0;i<data.length;i++)	{
			var dataString = data[i].string;
			var dataProp = data[i].prop;
			this.versionSearchString = data[i].versionSearch || data[i].identity;
			if (dataString) {
				if (dataString.indexOf(data[i].subString) != -1)
					return data[i].identity;
			}
			else if (dataProp)
				return data[i].identity;
		}
	},
	searchVersion: function (dataString) {
		var index = dataString.indexOf(this.versionSearchString);
		if (index == -1) return;
		return parseFloat(dataString.substring(index+this.versionSearchString.length+1));
	},
	dataBrowser: [
		{
			string: navigator.userAgent,
			subString: "Chrome",
			identity: "Chrome"
		},
		{ 	string: navigator.userAgent,
			subString: "OmniWeb",
			versionSearch: "OmniWeb/",
			identity: "OmniWeb"
		},
		{
			string: navigator.vendor,
			subString: "Apple",
			identity: "Safari",
			versionSearch: "Version"
		},
		{
			prop: window.opera,
			identity: "Opera"
		},
		{
			string: navigator.vendor,
			subString: "iCab",
			identity: "iCab"
		},
		{
			string: navigator.vendor,
			subString: "KDE",
			identity: "Konqueror"
		},
		{
			string: navigator.userAgent,
			subString: "Firefox",
			identity: "Firefox"
		},
		{
			string: navigator.vendor,
			subString: "Camino",
			identity: "Camino"
		},
		{		// for newer Netscapes (6+)
			string: navigator.userAgent,
			subString: "Netscape",
			identity: "Netscape"
		},
		{
			string: navigator.userAgent,
			subString: "MSIE",
			identity: "Explorer",
			versionSearch: "MSIE"
		},
		{
			string: navigator.userAgent,
			subString: "Gecko",
			identity: "Mozilla",
			versionSearch: "rv"
		},
		{ 		// for older Netscapes (4-)
			string: navigator.userAgent,
			subString: "Mozilla",
			identity: "Netscape",
			versionSearch: "Mozilla"
		}
	],
	dataOS : [
		{
			string: navigator.platform,
			subString: "Win",
			identity: "Windows"
		},
		{
			string: navigator.platform,
			subString: "Mac",
			identity: "Mac"
		},
		{
			   string: navigator.userAgent,
			   subString: "iPhone",
			   identity: "iPhone/iPod"
	    },
		{
			string: navigator.platform,
			subString: "Linux",
			identity: "Linux"
		}
	]

};
BrowserDetect.init();

//*****************************************************************

<!-- naviguateur accepte les cookies? -->
   var tmpcookie = new Date();
   chkcookie = (tmpcookie.getTime() + '');
   document.cookie = "chkcookie=" + chkcookie + "; path=/";
    if (document.cookie.indexOf(chkcookie,0) < 0) {
      window.location.href = 'sans_ck.php';
      }

<!-- fonction permettant de charger une feuille de style -->
function activerCSS(title) {
   var i, a, main;
   for(i=0; (a = document.getElementsByTagName("link")[i]); i++) {
     if(a.getAttribute("rel").indexOf("style") != -1
        && a.getAttribute("title")) {
       a.disabled = true;
       if(a.getAttribute("title") == title) a.disabled = false;
     }
   }  
}

<!-- génère le cookies -->
function creerCookies(nom,contenu) {
  document.cookie = nom + "=" + escape(contenu);
}

<!-- chargement de la feuille de style demandé -->
function creerStyle(nom,contenu) {
  creerCookies(nom,contenu);
  activerCSS(contenu);
}

<!-- obtient la valeur du cookie -->
function lectureCookies(nom) {
var deb,fin
  deb = document.cookie.indexOf(nom + "=")
  if (deb >= 0) {
    deb += nom.length + 1
    fin = document.cookie.indexOf(";",deb)
    if (fin < 0) fin = document.cookie.length
      return unescape(document.cookie.substring(deb,fin))
    }
  return ""
}
<!-- transfert la valeur du cookies dans la variable 'maValeurCookies' -->
function variableCook(nom) {
  maValeurCookies=lectureCookies(nom);
  if(maValeurCookies=="") {
   maValeurCookies='Style 1'; // si le cookies est vide, alors par défaut, c'est 'Style 1'
  }
}

var nomDuCookies = 'MonStyle';

<!-- procède à la lecture du cookies -->
variableCook(nomDuCookies);

<!-- procède au chargement de la feuille de style appropriée -->
activerCSS(maValeurCookies);