function browser_css( ) {
	 	var d,n,na,nua,win5,win6,mac,win6ie,win6ff,win5ie,win5ff,mac;
		d		= document;// shorthand so we don't have to write out document each time..
		n		= navigator;
		na		= n.appVersion;
		nua		= n.userAgent;
		win2	= ( nua.indexOf( 'NT 2' ) != -1 );
		win5	= ( nua.indexOf( 'NT 5' ) != -1 );
		win6	= ( nua.indexOf( 'NT 6' ) != -1 );
		mac		= ( na.indexOf( 'Mac' ) != -1 );
		//alert("appVersion = "+na);
		//alert("userAgent = "+nua);

		if (win6) {
			//alert("win6 = "+win6);
			win6ie = (nua.indexOf('MSIE') != -1);
			win6ff = (nua.indexOf('Firefox') != -1);
		}
		if (win5) {
			//alert("win5 = "+win5);
			win5ie = (nua.indexOf('MSIE 6') != -1);
			win5ie7 = (nua.indexOf('MSIE 7') != -1);
			win5ff = (nua.indexOf('Firefox') != -1);
			win5net = (nua.indexOf('Net') != -1);
		}
		if (win2) {
			//alert("win5 = "+win5);
			win2ie = (nua.indexOf('NET CLR') != -1);
		}

		if(mac) {
			//alert("mac = "+mac);
			retval="mac";
			//d.write('<link rel = "stylesheet" type = "text/css" href = "css/mac.css" />');
		} else if(win6ie) {
			//alert("win6ie css = "+win6ie);
			retval="win6ie";
			d.write('<link rel = "stylesheet" type = "text/css" href = "css/win6ie.css" />');
		} else if(win6ff) {
			//alert("win6ff css 2 = "+win6ff);
			retval="win6ff";
			d.write('<link rel = "stylesheet" type = "text/css" href = "css/win6ff.css" />');
		} else if(win5ie7) {
			//alert("win5ie css = "+win5ie);
			retval="win5ie7";
			d.write('<link rel = "stylesheet" type = "text/css" href = "css/win6ie.css" />');
		} else if(win5ie) {
			//alert("win5ie css = "+win5ie);
			retval="win5ie";
			d.write('<link rel = "stylesheet" type = "text/css" href = "css/win5ie.css" />');
		} else if(win5ff) {
			//alert("win5ff css 2 = "+win5ff);
			retval="win5ff";
			d.write('<link rel = "stylesheet" type = "text/css" href = "css/win5ff.css" />');
		} else if(win2ie) {
			//alert("win5ie css = "+win5ie);
			retval="win2ie";
			d.write('<link rel = "stylesheet" type = "text/css" href = "css/win2ie.css" />');
		} else if(win5net) {
			//alert("win5ie css = "+win5ie);
			retval="win5netscape";
			//d.write('<link rel = "stylesheet" type = "text/css" href = "css/win5net.css" />');
		}
		
		return retval;
		
	  }