var ua      = navigator.userAgent.toLowerCase();
var isOpera = ua.indexOf("opera") > -1;
var isIE    = !isOpera && ua.indexOf("msie") > -1;

if (isIE) {
	document.write("<link href='favicon.ico' type='image/x-icon' rel='shortcut icon'/>");
	document.write("<link href='favicon.ico' type='image/x-icon' rel='icon'/>");
} else {
	document.write("<link href='favicon.gif' type='image/gif' rel='shortcut icon'/>");
	document.write("<link href='favicon.gif' type='image/gif' rel='icon'/>");
}