var browser_type = navigator.appName;

switch (browser_type) {

case "Opera": document.write("<link href='/templates/micromedia/opera.css' rel='stylesheet' type='text/css' media='screen' />"); break; // Opera

case "Microsoft Internet Explorer":
	if (navigator.userAgent.toLowerCase().indexOf('msie 6') != -1) { document.write("<link href='/templates/micromedia/screen_ie6.css' rel='stylesheet' type='text/css' media='screen' />"); } // MSIE < v.7
	else { document.write("<link href='/templates/micromedia/screen.css' rel='stylesheet' type='text/css' media='screen' />"); } // MSIE >= v.7
	break;

case "Firefox": document.write("<link href='/templates/micromedia/mozilla.css' rel='stylesheet' type='text/css' media='screen' />"); break; // Firefox, Mozilla

case "Netscape": document.write("<link href='/templates/micromedia/netscape.css' rel='stylesheet' type='text/css' media='screen' />"); break; // Netscape

default: document.write("<link href='/templates/micromedia/mozilla.css' rel='stylesheet' type='text/css' media='screen' />"); break; // tutti quelli non identificati

}