var os = navigator.platform;
var brName = navigator.appName.charAt(0);
var brVer = navigator.appVersion.charAt(0);
var brType ="";

if(os == "Win32"){
if((brName == "N") && (brVer >= 4)){
cssSrc = '<LINK REL="stylesheet" TYPE="text/css" HREF="win_nc.css">' ;
} else if((brName == "M") && (brVer >= 4)) {
cssSrc = '<LINK REL="stylesheet" TYPE="text/css" HREF="win_ie.css">' ;
}
} else if(os == "MacPPC"){
if((brName == "N") && (brVer >= 4)){
cssSrc = '<LINK REL="stylesheet" TYPE="text/css" HREF="mac_nc.css">' ;
} else if((brName == "M") && (brVer >= 4)) {
cssSrc = '<LINK REL="stylesheet" TYPE="text/css" HREF="mac_ie.css">' ;
}
}
document.write( cssSrc ) ;