diff --git a/module/custom/control.php b/module/custom/control.php
index 91efeb1765..b80c365c94 100644
--- a/module/custom/control.php
+++ b/module/custom/control.php
@@ -46,6 +46,10 @@ class custom extends control
                 $value  = $_POST['values'][$index];
                 if(!$value or !$key) continue;
                 $system = $_POST['systems'][$index];
+
+                /* the length of role is 20, check it when save. */
+                if($module == 'user' and $field == 'roleList' and strlen($key) > 20) die(js::alert($this->lang->custom->notice->userRole));
+
                 $this->custom->setItem("{$lang}.{$module}.{$field}.{$key}.{$system}", $value);
             }
             if(dao::isError()) die(js::error(dao::getError()));
diff --git a/module/custom/lang/en.php b/module/custom/lang/en.php
index 5454f0cb0f..47cbec20d6 100644
--- a/module/custom/lang/en.php
+++ b/module/custom/lang/en.php
@@ -61,3 +61,6 @@ $lang->custom->currentLang = 'For current language';
 $lang->custom->allLang     = 'For all language';
 
 $lang->custom->confirmRestore = 'Are you sure to restore the default lang setting?';
+
+$lang->custom->notice = new stdclass();
+$lang->custom->notice->userRole = 'The length of key must be less than 20!';
diff --git a/module/custom/lang/zh-cn.php b/module/custom/lang/zh-cn.php
index 65a42665ce..2edeb44bac 100644
--- a/module/custom/lang/zh-cn.php
+++ b/module/custom/lang/zh-cn.php
@@ -61,3 +61,6 @@ $lang->custom->currentLang = '适用当前语言';
 $lang->custom->allLang     = '适用所有语言';
 
 $lang->custom->confirmRestore = '是否要恢复默认语言配置？';
+
+$lang->custom->notice = new stdclass();
+$lang->custom->notice->userRole = '键的长度必须小于20个字符！';
diff --git a/module/custom/view/set.html.php b/module/custom/view/set.html.php
index fa761b0165..3f28999418 100644
--- a/module/custom/view/set.html.php
+++ b/module/custom/view/set.html.php
@@ -55,7 +55,7 @@ EOT;
   </div>
 </div>
 <div class='main'>
-  <form method='post' class='form-condensed'>
+  <form method='post' class='form-condensed' target='hiddenwin'>
     <div class='panel panel-sm'>
       <div class='panel-heading'>
         <strong><?php echo $lang->custom->object[$module] . ' >> ' . $lang->custom->$module->fields[$field]?></strong>