private final void giveKeyEnventToBrowser() {
   boolean b1 = mBrowser.isLockBackKey();
   boolean b2 = mBrowser.isSpaceShown();
   if (b1 && !b2) {
     mBrowser.onAppKeyPress(EUExCallback.F_C_Key_Back);
   } else {
     mBrowser.goBack();
   }
 }
 @Override
 public final boolean onKeyUp(int keyCode, KeyEvent event) {
   if (!mKeyDown) {
     return true;
   }
   mKeyDown = false;
   switch (keyCode) {
     case KeyEvent.KEYCODE_BACK:
       if (customViewShown()) {
         hideCustomView();
       } else {
         giveKeyEnventToBrowser();
       }
       return true;
     case KeyEvent.KEYCODE_MENU:
       if (mBrowser.isLockMenuKey() && !mBrowser.isSpaceShown()) {
         mBrowser.onAppKeyPress(EUExCallback.F_C_Key_Menu);
         return true;
       }
       break;
   }
   return super.onKeyUp(keyCode, event);
 }