var browser_version = parseFloat(navigator.appVersion.replace(/^.*MSIE /, ''))
var browser_type = navigator.appName;

if (browser_type == "Microsoft Internet Explorer" && (browser_version <= 6)) {
document.write("<link rel='stylesheet' href='/css/fix_ie6.css' type='text/css'>");
}
else if (browser_type == "Microsoft Internet Explorer" && (browser_version == 7 || browser_version == 8)) {
document.write("<link rel='stylesheet' href='/css/fix_ie7.css' type='text/css'>");
}