var BrowserDetect = { 
       init: function () { 
          this.browser = this.searchString(this.dataBrowser) || "An unknown browser"; 
          this.version = this.searchVersion(navigator.userAgent) 
             || this.searchVersion(navigator.appVersion) 
             || "an unknown version"; 
          this.OS = this.searchString(this.dataOS) || "an unknown OS"; 
       }, 
    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: "OmniWeb", 
          versionSearch: "OmniWeb/", 
          identity: "OmniWeb" 
       }, 
    { 
       string: navigator.vendor, 
       subString: "Apple", 
       identity: "Safari" 
    }, 
    { 
       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.platform, 
       subString: "Linux", 
       identity: "Linux" 
    } 
] 

}; 
BrowserDetect.init(); 

//script para poner estilos distintos para cada navegador 
if (BrowserDetect.browser == "Firefox") { 
    document.write("<LINK REL='stylesheet' HREF='css/firefox.css' TYPE='text/css'>"); 
} 
else { 
    if (BrowserDetect.browser == "Explorer"){ 
       if (BrowserDetect.version>=7){ 
          document.write("<LINK REL='stylesheet' HREF='css/ie7.css' TYPE='text/css'>"); 
       }else{ 
          document.write("<LINK REL='stylesheet' HREF='css/ie6.css' TYPE='text/css'>"); 
       } 
    }else{ 
       if (BrowserDetect.browser == "Opera"){ 
          if (BrowserDetect.version<9){ 
             document.write("<LINK REL='stylesheet' HREF='css/firefox.css' TYPE='text/css'>"); 
          }else{ 
             document.write("<LINK REL='stylesheet' HREF='css/firefox.css' TYPE='text/css'>"); 
          } 
       }else{ 
          document.write("<LINK REL='stylesheet' HREF='css/firefox.css' TYPE='text/css'>"); 
       } 
    } 
}