var agt=navigator.userAgent.toLowerCase(); 
var is_major = parseInt(navigator.appVersion); 
var is_ie   = (agt.indexOf("msie") != -1); 
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_ie3  = (is_ie && (is_major < 4)); 
var is_ie4  = (is_ie && (is_major == 4) && (agt.indexOf("msie 5.0")==-1) ); 
var is_ie5up  = (is_ie  && !is_ie3 && !is_ie4);
var is_nav5up = (is_nav && (is_major >= 5)); 
var is_mac    = (agt.indexOf("mac")!=-1); 

if (is_mac && !(is_ie5up || is_nav5up)) 
{
	// old mac browser 
	document.write("<LINK REL=stylesheet HREF='/scripts/oldmac.css' TYPE='text/css'>");
}
else if (!is_mac && !is_ie && !is_nav5up) 
{
	// non stylesheet browser i.e netscape pre version 5
	document.write("<LINK REL=stylesheet HREF='/scripts/oldpc.css' TYPE='text/css'>");
}
else
{
	// its css complaint browsers all the way
	document.write("<LINK REL=stylesheet HREF='/scripts/default.css' TYPE='text/css'>"); 

}