// スタイルシートの振り分け
if( navigator.appVersion.indexOf("Mac")>1){
 if( navigator.userAgent.indexOf("Opera")!=-1){
   document.write("<link href='css/a_mo.css' rel='stylesheet' type='text/css' media='screen'>"); // Operaの場合  
 }else if( navigator.appName.charAt(0)=="M"){
  document.write("<link href='css/a_mm.css' rel='stylesheet' type='text/css' media='screen'>"); // IEの場合
 }else{
 		if( navigator.appVersion.charAt(0) >= 5){
		document.write("<link href='css/a_mn.css' rel='stylesheet' type='text/css' media='screen'>");// Netscape5.0以上
		}else{ 
		document.write("<link href='css/a_mn_4.css' rel='stylesheet' type='text/css' media='screen'>");// Netscape5.0以下
		}
 }
} else {
 if( navigator.userAgent.indexOf("Opera")!=-1){
   document.write("<link href='css/a_wo.css' rel='stylesheet' type='text/css' media='screen'>"); // Operaの場合 
 }else if( navigator.appName.charAt(0)=="N"){
 		if( navigator.appVersion.charAt(0) >= 5){
		document.write("<link href='css/a_wn_5.css' rel='stylesheet' type='text/css' media='screen'>");// Netscape5.0以上
		}else{ 
		document.write("<link href='css/a_wn_4.css' rel='stylesheet' type='text/css' media='screen'>");// Netscape5.0以下
		}
 }else{
  document.write("<link href='css/a_wm.css' rel='stylesheet' type='text/css' media='screen'>"); // IEとその他の場合
 }
}