diff --git a/MCU/MCU_REAL_FINAL/menu.c b/MCU/MCU_REAL_FINAL/menu.c
index d9c81e3..6273e04 100644
--- a/MCU/MCU_REAL_FINAL/menu.c
+++ b/MCU/MCU_REAL_FINAL/menu.c
@@ -67,6 +67,8 @@ void m_mainmenu(struct _menu* this)
     {
       if(local[0] > 1)
         local[0]--;
+      if(local[0] == 0)
+        local[0] = 3;
 
       opr = idle;
       drawMAINMENU(local[0]);
@@ -109,7 +111,7 @@ void m_block(struct _menu* this)
   if(opr == confirm)
     {
       opr = idle;
-			clear();
+      clear();
       blockDestroy();
       NOW = &M_MAINMENU;
       return;
@@ -184,7 +186,7 @@ void m_about(struct _menu* this)
       opr = idle;
       NOW = &M_MAINMENU;				//转向下一菜单
       clear();
-			//若满足隐藏条件，清空排行榜
+      //若满足隐藏条件，清空排行榜
       if(local[2] >= 30 && local[3] >= 30)
         {
           IapProgramByte(IAP_ADDRESS + 0, 0);