var isMac ,IEmac ,NS4 ,NS6 ,NS7 ,IE4plus ,IE4 ,IE5 ,IE6 ,IE7 ,IE5plus ,ver4 ,IEMajor ,MSIE ;
var FIREFOX ,FIREFOX14 ,FIREFOX15 ,FIREFOX14plus ;
function Is()
{
   isMac = (navigator.appVersion.indexOf("Mac")!=-1) ? true : false;
   IEmac = ((document.all)&&(isMac)) ? true : false;

   NS4 = (document.layers) ? true : false;
   NS6 = (!document.layers) && (navigator.userAgent.indexOf('Netscape')!=-1)?true:false;
   NS7 = (!document.layers) && (navigator.userAgent.indexOf('Netscape/7')!=-1)?true:false;
   NS6plus = NS6 || NS7;

   IE4plus = (document.all) ? true : false;
   MSIE = ((document.all)&&(navigator.appVersion.indexOf("MSIE")!=-1)) ? true : false;
   IE4 = ((document.all)&&(navigator.appVersion.indexOf("MSIE 4.")!=-1)) ? true : false;
   IE5 = ((document.all)&&(navigator.appVersion.indexOf("MSIE 5.")!=-1)) ? true : false;
   IE6 = ((document.all)&&(navigator.appVersion.indexOf("MSIE 6.")!=-1)) ? true : false;
   IE7 = ((document.all)&&(navigator.appVersion.indexOf("MSIE 7.")!=-1)) ? true : false;
   IE5plus = IE5 || IE6 || IE7;

   ver4 = (NS4 || IE4plus) ? true : false;
   IEMajor = 0;

   FIREFOX = ((!document.layers) && (navigator.userAgent.indexOf('Firefox')!=-1)) ? true:false;
   FIREFOX14 = (!document.layers) && (navigator.userAgent.indexOf('Firefox/1.4')!=-1)?true:false;
   FIREFOX15 = (!document.layers) && (navigator.userAgent.indexOf('Firefox/1.5')!=-1)?true:false;
   FIREFOX14plus = FIREFOX14 || FIREFOX15;
   //alert ("FIREFOX is 1 " + FIREFOX);  // why false?
}
Is();
//alert ("FIREFOX is 2 " + FIREFOX);	// why false?
//alert ("MSIE = " + MSIE);				// work
//alert ("FIREFOX = " + FIREFOX);		// work