Google Analytics Javascript errors tracking

gaerror.js

$(window).error(function (error) {
    if (error && error.originalEvent) {
		error = error.originalEvent;
		var message, url, line;
		if (error && error.message) {
			message = error.message;
			url = getfilename(error.filename);
			line = error.lineno;
		} else {
			message = "(message empty)";
			url = getfilename(document.location.href);
			line = "?";
		}
		gajserror(message,url,line);
    }
    return true;
});

window.onerror = function(message, url, line) {
	gajserror(message,url,line);
    return true;
};

function gajserror(message,url,line) {
	_gaq.push(["_trackEvent", "JS Exception Error", message, url + " (" + line + ")", 0, true]);
};

function getfilename(url) {
	url = url.substring(0, (url.indexOf("#") == -1) ? url.length : url.indexOf("#"));
	url = url.substring(0, (url.indexOf("?") == -1) ? url.length : url.indexOf("?"));
	url = url.substring(url.lastIndexOf("/") + 1, url.length);
	return url;
}