diff --git a/web/public/js/utils.js b/web/public/js/utils.js
index 95527608..f8296d44 100644
--- a/web/public/js/utils.js
+++ b/web/public/js/utils.js
@@ -132,7 +132,27 @@ window.teaweb = {
 		return (Math.round(bytes * 100 / 1024 / 1024 / 1024 / 1024 / 1024) / 100) + "P";
 	},
 	formatNumber: function (x) {
-		return x.toString().replace(/\B(?<!\.\d*)(?=(\d{3})+(?!\d))/g, ", ");
+		if (x == null) {
+			return "null"
+		}
+		let s = x.toString()
+		let dotIndex = s.indexOf(".")
+		if (dotIndex >= 0) {
+			return this.formatNumber(s.substring(0, dotIndex)) + "." + s.substring(dotIndex + 1)
+		}
+
+		if (s.length <= 3) {
+			return s;
+		}
+		let result = []
+		for (let i = 0; i < Math.floor(s.length / 3); i++) {
+			let start = s.length - (i + 1) * 3
+			result.push(s.substring(start, start + 3))
+		}
+		if (s.length % 3 != 0) {
+			result.push(s.substring(0, s.length % 3))
+		}
+		return result.reverse().join(", ")
 	},
 	formatCount: function (x) {
 		let unit = ""
diff --git a/web/views/@default/dashboard/boards/index.js b/web/views/@default/dashboard/boards/index.js
index eed64b4f..9b5fc593 100644
--- a/web/views/@default/dashboard/boards/index.js
+++ b/web/views/@default/dashboard/boards/index.js
@@ -58,7 +58,6 @@ Tea.context(function () {
 		})
 		let chartBox = document.getElementById(chartId)
 		let chart = teaweb.initChart(chartBox)
-		let that = this
 		let option = {
 			xAxis: {
 				data: stats.map(function (v) {