diff --git a/GuiLite.h b/GuiLite.h
index fa2b8fd..6ec706c 100644
--- a/GuiLite.h
+++ b/GuiLite.h
@@ -186,13 +186,13 @@ protected:
 			}
 			if (MSG_TYPE_USR == p_entry->msgType)
 			{
-				ms_usr_map_entries[ms_user_map_size] = *p_entry;
-				ms_usr_map_entries[ms_user_map_size].object = this;
-				ms_user_map_size++;
 				if (USR_MSG_MAX == ms_user_map_size)
 				{
 					ASSERT(false);
 				}
+				ms_usr_map_entries[ms_user_map_size] = *p_entry;
+				ms_usr_map_entries[ms_user_map_size].object = this;
+				ms_user_map_size++;
 			}
 			else
 			{
@@ -2403,11 +2403,12 @@ public:
 	virtual void on_paint()
 	{
 		c_rect rect;
+		unsigned int bg_color = m_bg_color ? m_bg_color : m_parent->get_bg_color();
 		get_screen_rect(rect);
 		if (m_str)
 		{
-			m_surface->fill_rect(rect.m_left, rect.m_top, rect.m_right, rect.m_bottom, m_parent->get_bg_color(), m_z_order);
-			c_word::draw_string_in_rect(m_surface, m_z_order, m_str, rect, m_font_type, m_font_color, m_parent->get_bg_color(), ALIGN_LEFT | ALIGN_VCENTER);
+			m_surface->fill_rect(rect.m_left, rect.m_top, rect.m_right, rect.m_bottom, bg_color, m_z_order);
+			c_word::draw_string_in_rect(m_surface, m_z_order, m_str, rect, m_font_type, m_font_color, bg_color, ALIGN_LEFT | ALIGN_VCENTER);
 		}
 	}
 protected:
diff --git a/documents/HowToUse.md b/documents/HowToUse.md
index f51d02e..5cd423f 100644
--- a/documents/HowToUse.md
+++ b/documents/HowToUse.md
@@ -17,7 +17,7 @@ UIcode.cpp:
 Prerequisite: Windows & Visul Studio 2013/2015/2017/2019
 - Open "GuiLite.sln" by Visual Studio
 - Click `Build Solution`
-- Output here: \GuiLite\workspace\Debug(Release)\GuiLite.lib
+- Output here: GuiLite\workspace\Debug(Release)\GuiLite.lib
 
 FAQ: Error when open GuiLite project with Visual Studio, reconfigure the project to match your computer like this:
 
@@ -29,7 +29,7 @@ cd GuiLite/workspace
 cmake .
 make
 
-# Output here: /GuiLite/workspace/libGuiLite.a
+# Output here: GuiLite/workspace/libGuiLite.a
 ```
 
 ## Build GuiLite libary for ARM Linux?
@@ -49,7 +49,7 @@ cmake -D CMAKE_C_COMPILER="/usr/bin/arm-linux-gnueabi-gcc" -D CMAKE_CXX_COMPILER
 cmake -D CMAKE_C_COMPILER="/usr/bin/aarch64-linux-gnu-gcc" -D CMAKE_CXX_COMPILER="/usr/bin/aarch64-linux-gnu-g++" .
 make
 ```
-Output here: /GuiLite/workspace/libGuiLite.a
+Output here: GuiLite/workspace/libGuiLite.a
 
 ## How to build GuiLite libary for any MCU?
 ### Prerequisite: Install Keil uvsion 5.6 or above.
@@ -58,7 +58,7 @@ Output here: /GuiLite/workspace/libGuiLite.a
 - Implement function(e.g, thread_sleep) in `core\src\adapter\api_unknow.cpp` to meet your need.
 - Choose your Device type(Default: STM32F103ZE) from option for target.
 - Build GuiLite.
-- Output here: /GuiLite/workspace/Objects/GuiLite.lib
+- Output here: GuiLite/workspace/Objects/GuiLite.lib
 
 ## Build header-only GuiLite.h?
 ```bash
diff --git a/workspace/core_include/cmd_target.h b/workspace/core_include/cmd_target.h
index 0c0bd0f..64794bd 100644
--- a/workspace/core_include/cmd_target.h
+++ b/workspace/core_include/cmd_target.h
@@ -93,13 +93,13 @@ protected:
 
 			if (MSG_TYPE_USR == p_entry->msgType)
 			{
-				ms_usr_map_entries[ms_user_map_size] = *p_entry;
-				ms_usr_map_entries[ms_user_map_size].object = this;
-				ms_user_map_size++;
 				if (USR_MSG_MAX == ms_user_map_size)
 				{
 					ASSERT(false);
 				}
+				ms_usr_map_entries[ms_user_map_size] = *p_entry;
+				ms_usr_map_entries[ms_user_map_size].object = this;
+				ms_user_map_size++;
 			}
 			else
 			{
diff --git a/workspace/widgets_include/label.h b/workspace/widgets_include/label.h
index 599446e..41b521e 100644
--- a/workspace/widgets_include/label.h
+++ b/workspace/widgets_include/label.h
@@ -16,12 +16,12 @@ public:
 	virtual void on_paint()
 	{
 		c_rect rect;
+		unsigned int bg_color = m_bg_color ? m_bg_color : m_parent->get_bg_color();
 		get_screen_rect(rect);
-
 		if (m_str)
 		{
-			m_surface->fill_rect(rect.m_left, rect.m_top, rect.m_right, rect.m_bottom, m_parent->get_bg_color(), m_z_order);
-			c_word::draw_string_in_rect(m_surface, m_z_order, m_str, rect, m_font_type, m_font_color, m_parent->get_bg_color(), ALIGN_LEFT | ALIGN_VCENTER);
+			m_surface->fill_rect(rect.m_left, rect.m_top, rect.m_right, rect.m_bottom, bg_color, m_z_order);
+			c_word::draw_string_in_rect(m_surface, m_z_order, m_str, rect, m_font_type, m_font_color, bg_color, ALIGN_LEFT | ALIGN_VCENTER);
 		}
 	}
 protected: