diff --git a/lib/md2html.js b/lib/md2html.js
index 7ead2ec..ff0d5d8 100644
--- a/lib/md2html.js
+++ b/lib/md2html.js
@@ -1,8 +1,8 @@
-let md = require('markdown-it')({
+var md = require('markdown-it')({
   html: true
 });
-let markdownItAttrs = require('markdown-it-attrs');
-let fs = require('fs');
+var markdownItAttrs = require('markdown-it-attrs');
+var fs = require('fs');
 var cheerio = require('cheerio');
 
 
@@ -12,9 +12,9 @@ md.use(markdownItAttrs);
 function md2Html(filename, callback) {
 	fs.readFile(filename, (err, data) => {
 		if (err) throw err;
-		let fileStr = data.toString();
-		let result = parseSource(fileStr);
-		let html = md.render(result);
+		var fileStr = data.toString();
+		var result = parseSource(fileStr);
+		var html = md.render(result);
 		html = parseScript(html);
 
 		callback(html);
@@ -70,8 +70,8 @@ function parseSource(str) {
 
 
 function replaceStr(str, key, pos, padding) {
-	let arr = str.split('');
-	let replace = key2attr(key);
+	var arr = str.split('');
+	var replace = key2attr(key);
 	if (padding) {
 		replace = padding + replace;
 	}
@@ -81,23 +81,23 @@ function replaceStr(str, key, pos, padding) {
 }
 
 function key2attr(key) {
-	let k = key.replace(/[-+]{3,}/, '').trim();
+	var k = key.replace(/[-+]{3,}/, '').trim();
 	if (k === '') return '\n<section>\n';
 
-	let html = '\n<section ';
-	let attrs = k.split(/\s/);
+	var html = '\n<section ';
+	var attrs = k.split(/\s/);
 
 	attrs.forEach((attr) => {
 		if (attr.split('=').length === 2) {
 			html += attr + ' ';
 		} else {
-			let classIdArr = attr.match(/[.#][a-zA-Z-]+/g);
-			let classArr = classIdArr.filter((val) => {
+			var classIdArr = attr.match(/[.#][a-zA-Z-]+/g);
+			var classArr = classIdArr.filter((val) => {
 				return val.indexOf('.') >= 0
 			}).map((val) => {
 				return val.substr(1)
 			});
-			let idArr = classIdArr.filter((val) => {
+			var idArr = classIdArr.filter((val) => {
 				return val.indexOf('#') >= 0
 			}).map((val) => {
 				return val.substr(1)
@@ -123,11 +123,11 @@ function key2attr(key) {
 
 function parseScript(html){
 	console.log(html)
-	let $ = cheerio.load(html);
+	var $ = cheerio.load(html);
 	console.log($('script').parent().attr('id'))
 	$('script').each((i, elem)=>{
-		let $script = $(elem);
-		let $section = $script.parents('section');
+		var $script = $(elem);
+		var $section = $script.parents('section');
 		$section.attr('data-script', encodeURIComponent($script.html()) );
 		$script.remove();
 	})