if (navigator.userAgent.indexOf("Netscape")!=-1) {
   document.write('<link rel="stylesheet" type="text/css" href="css/mac_nn7.css">');
}
/*
else if (navigator.userAgent.indexOf("MSIE")!=-1) {
   document.write('<link rel="stylesheet" type="text/css" href="ie6x.css">');
}
*/
else if (navigator.appVersion.indexOf("MSIE 6")!= -1) {
   document.write('<link rel="stylesheet" type="text/css" href="css/style_ie6.css">');
}
else if (navigator.appVersion.indexOf("MSIE 7")!= -1) {
   document.write('<link rel="stylesheet" type="text/css" href="css/style_ie7.css">');
}
else if (navigator.appVersion.indexOf("MSIE 8")!= -1) {
   document.write('<link rel="stylesheet" type="text/css" href="css/style_ie8.css">');
}
else if (navigator.userAgent.indexOf("Safari") != -1) {
   document.write('<link rel="stylesheet" type="text/css" href="css/mac_style.css">');
}
else {
   document.write('<link rel="stylesheet" type="text/css" href="css/style.css">');
}