Complete method to determine client browser type

var browseragent=navigator.useragent.tolowercase ();
var browserisopera=browseragent.indexof ("opera")!=-1;
var browserisfirefox=browseragent.indexof ("Firefox")!=-1;
var browserisnetscape=browseragent.indexof ("Netscape")!=-1;
var browserisie=browseragent.indexof ("MSIE")!=-1&& (document.all&&true);
if (Browserisie)
{
Window.attachevent ("onload", autoheight, NULL);
Window.attachevent ("onload", initializeobjects, NULL);
}
Else
{
Document.addeventlistener ("domcontentloaded", autoheight, NULL);
Document.addeventlistener ("domcontentloaded", initializeobjects, NULL);
}

A second method:

Get browser type
function Browser () {
var UA, S;
This.isie = false;
This.isns = false;
This.isop = false;
THIS.ISSF = false;
THIS.ISFF = false;
UA = Navigator.userAgent.toLowerCase ();
s = "Opera";
This.isop = Ua.indexof (s)!=-1;
s = "MSIE";
This.isie = Ua.indexof (s)!=-1;
s = "Netscape";
this.isns= Ua.indexof (s)!=-1;
s = "Gecko";
This.isns = Ua.indexof (s)!=-1;
s = "Safari";
THIS.ISSF = Ua.indexof (s)!=-1;
S= "Firefox"
This.isff=ua.indexof (s)!=-1;
}

var browser = new browser ();

if ((!BROWSER.ISSF) && (!BROWSER.ISOP)

{

}