function minifyFile(resHtml, outputPath) {
	var resHtml = minify(resHtml, opt, function (err) {
		if (err) {
			console.error('error will processing file.');
		}
	});

	console.log('');
	console.log('Output file name : ' + outputPath);
	console.log('');
	writeFile(resHtml, outputPath);
}