解决安卓扫码问题
diff --git a/www/billdetail.html b/www/billdetail.html
index e419a98..8289dbf 100644
--- a/www/billdetail.html
+++ b/www/billdetail.html
@@ -16,7 +16,7 @@
 
 <body>
     <header class="aui-bar aui-bar-nav" style="padding-top:25px;">
-        <a class="aui-pull-left" href="javascript:window.history.go(-1)">
+        <a class="aui-pull-left" href="javascript:app.toBack();">
             <span class="aui-iconfont aui-icon-left"></span>
         </a>
         <div class="aui-title">账单详情</div>