diff --git a/GUI/inc/SGUI_VariableBox.h b/GUI/inc/SGUI_VariableBox.h
index e72741c..9c416db 100644
--- a/GUI/inc/SGUI_VariableBox.h
+++ b/GUI/inc/SGUI_VariableBox.h
@@ -27,7 +27,7 @@ typedef struct
 	SGUI_SIZE	Width;
 	SGUI_SIZE	FocusIndex;
 	SGUI_SIZE	MaxTextLength;
-	SGUI_PSZSTR		Value;
+	SGUI_PSZSTR	Value;
 }SGUI_TEXT_VARBOX_STRUCT;
 
 typedef enum
diff --git a/GUI/src/SGUI_VariableBox.c b/GUI/src/SGUI_VariableBox.c
index eaf0ed7..b85b223 100644
--- a/GUI/src/SGUI_VariableBox.c
+++ b/GUI/src/SGUI_VariableBox.c
@@ -151,18 +151,14 @@ void SGUI_TextVariableBox_UpdateCharacter(SGUI_TEXT_VARBOX_STRUCT* pstTextValue,
 		if(pstTextValue->MaxTextLength > VARBOX_TEXT_LENGTH_MAX)
 		{
 			pstTextValue->MaxTextLength = VARBOX_TEXT_LENGTH_MAX;
-			uiFocusIndexMax = VARBOX_TEXT_LENGTH_MAX-1;
-		}
-		else
-		{
-			uiFocusIndexMax = pstTextValue->MaxTextLength-1;
 		}
+		uiFocusIndexMax = pstTextValue->MaxTextLength-1;
 		// Ignore too long text string.
 		uiTextLength = SGUI_Common_StringLength(pstTextValue->Value);
 		if(uiTextLength > pstTextValue->MaxTextLength)
 		{
 			uiTextLength = pstTextValue->MaxTextLength;
-			*(pstTextValue->Value+uiFocusIndexMax) = '\0';
+			*(pstTextValue->Value+uiTextLength) = '\0';
             // Point at to last character position if index is more then string length.
 			if(pstTextValue->FocusIndex > uiFocusIndexMax)
 			{
diff --git a/HMI/src/HMI_Demo05_VariableBox.c b/HMI/src/HMI_Demo05_VariableBox.c
index e0a56e1..3185faf 100644
--- a/HMI/src/HMI_Demo05_VariableBox.c
+++ b/HMI/src/HMI_Demo05_VariableBox.c
@@ -40,7 +40,7 @@ static void				HMI_DemoVariableBox_DrawFrame(SGUI_PSZSTR szTitle);
 //=======================================================================//
 static SGUI_INT_VARBOX_STRUCT	stNumberVariableBox =	{VARIABLE_BOX_POSX+2, VARIABLE_BOX_NUMBER_POSY+2, VARIABLE_BOX_WIDTH, -50, 100, 0};
 static char						arrTextVariable[TEXT_VARIABLE_LENGTH+1] = {"ABCDEFG"};
-static SGUI_TEXT_VARBOX_STRUCT	stTextVariableBox =		{VARIABLE_BOX_POSX+2, VARIABLE_BOX_TEXT_POSY+2, VARIABLE_BOX_WIDTH, 0, TEXT_VARIABLE_LENGTH-1, arrTextVariable};
+static SGUI_TEXT_VARBOX_STRUCT	stTextVariableBox =		{VARIABLE_BOX_POSX+2, VARIABLE_BOX_TEXT_POSY+2, VARIABLE_BOX_WIDTH, 0, TEXT_VARIABLE_LENGTH, arrTextVariable};
 static const char				stFrameTitleDefault[] =	{"数值/文本编辑演示"};
 static const char*				szFrameTitle =			stFrameTitleDefault;
 static uint16_t					uiFocusedFlag;
@@ -205,7 +205,7 @@ int32_t HMI_DemoVariableBox_OnExternalEvent(uint32_t uiScreenID,const void* pstP
 			{
 				if(1 == uiFocusedFlag)
 				{
-					if(stTextVariableBox.FocusIndex < (TEXT_VARIABLE_LENGTH))
+					if(stTextVariableBox.FocusIndex < (stTextVariableBox.MaxTextLength-1))
 					{
 						stTextVariableBox.FocusIndex++;
 						SGUI_TextVariableBox_ChangeCharacter(&stTextVariableBox, GUI_DRAW_REVERSE, GUI_TEXT_ASCII, SGUI_TXT_VARBOX_OPT_NONE);