if (window.navigator.userAgent.indexOf ("Opera") >= 0) ua = 'Opera';
else if (window.navigator.userAgent.indexOf ("Gecko") >= 0) ua = 'Netscape';
else if (window.navigator.userAgent.indexOf ("MSIE") >= 0) ua = 'Explorer';
else ua = 'other'; // Неизвестные мне браузеры

if(ua=='Explorer'){
	document.writeln("<LINK rel='STYLESHEET' type='text/css' href='/upload/ie.css'>");
} else if(ua=='Opera') {
	document.writeln("<LINK rel='STYLESHEET' type='text/css' href='/upload/opera.css'>");
}  else if(ua=='Netscape') {
	document.writeln("<LINK rel='STYLESHEET' type='text/css' href='/upload/moz.css'>");
} else {
	document.writeln("<LINK rel='STYLESHEET' type='text/css' href='/upload/all.css'>");
}