var WIN=navigator.userAgent.indexOf('Win')!=-1;
var MAC=navigator.userAgent.indexOf('Mac')!=-1;
var bName=navigator.appName.charAt(0);
var vNum=navigator.appVersion.charAt(0);

var WIE=(WIN && bName=="M");
var WNS4=(WIN && bName=="N" && vNum<5);
var WNS=(WIN && bName=="N" && vNum>=5);
var MIE=(MAC && bName=="M");
var MNS4=(MAC && bName=="N" && vNum<5);
var MNS=(MAC && bName=="N" && vNum>=5);

if(WIE){
	document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"script/win_ie.css\">");//Win IE
}else if(WNS4){
	document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"script/win_ns4.css\">");//Win NS4.x
}else if(WNS){
	document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"script/win_ns6.css\">");//Win NS6�`
}else if(MIE){
	document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"script/mac_ie.css\">");//Mac IE
}else if(MNS4){
	document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"script/mac_ns4.css\">");//Mac NS4.x
}else if(MNS){
	document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"script/mac_ns6.css\">");//Mac NS6�`
}