if (navigator.userAgent.indexOf("MSIE") == -1) {
	document.write('<link rel="STYLESHEET" type="text/css" href="../ext/app_global_styles_net.css">'); // css per netscape 
} else {
	document.write('<link rel="STYLESHEET" type="text/css" href="../ext/app_global_styles_ie.css">');  // css per explorer
	  }