diff --git a/sysgo/UI/Emulator/rom_so_confirm_page.go b/sysgo/UI/Emulator/rom_so_confirm_page.go
index 364cbab..380c382 100644
--- a/sysgo/UI/Emulator/rom_so_confirm_page.go
+++ b/sysgo/UI/Emulator/rom_so_confirm_page.go
@@ -80,9 +80,10 @@ func (self *RomSoConfirmPage) KeyDown(ev *event.Event) {
   }
   
   if ev.Data["Key"] == UI.CurKeys["B"] {
-    if UI.CheckBattery < 5 {
+    bat := UI.CheckBattery()
+    if bat < 5 && bat >= 0 {
       self.SnapMsg("Battery must over 5%")
-    }else {
+    }else { // -1 or something else,
       if self.DownloadPage == nil {
         self.DownloadPage = UI.NewDownloadProcessPage()
         self.DownloadPage.Screen = self.Screen
diff --git a/sysgo/UI/util_funcs.go b/sysgo/UI/util_funcs.go
index 2c5e9ce..8ea615e 100644
--- a/sysgo/UI/util_funcs.go
+++ b/sysgo/UI/util_funcs.go
@@ -215,8 +215,8 @@ func GetUid(path string) int {
 }
 
 func  CheckBattery() int {
-  if UI.FileExists(sysgo.Battery) == false {
-    return
+  if FileExists(sysgo.Battery) == false {
+    return -1
   }
   batinfos,err := ReadLines(sysgo.Battery)
   if err == nil {