修改屏幕亮度和图标
diff --git a/www/qrcode.html b/www/qrcode.html
index ca6cb07..48e9b69 100644
--- a/www/qrcode.html
+++ b/www/qrcode.html
@@ -15,7 +15,7 @@
 </head>
 <body style="background: #fff"  >
     <header class="aui-bar aui-bar-nav" style="padding-top:25px;">
-        <a class="aui-pull-left" href="main.html">
+        <a class="aui-pull-left" href="app.backTo()">
             <span class="aui-iconfont aui-icon-left"></span>
         </a>
         <div class="aui-title">付款码</div>