diff --git a/script/lib.sh b/script/lib.sh
index 032adae..5149dea 100644
--- a/script/lib.sh
+++ b/script/lib.sh
@@ -276,7 +276,6 @@ function deactivate_and_close(){
 # ******************************************************************************* 
 #              Delete the nwe volume if overwrite install, and close all
 # ******************************************************************************* 
-
 function on_unexpected_installer_quit(){
 	echo "***** ERROR : The GUI/TUI installer terminated unexpectedly. *****" 
 	if [ "${OVERWRITEINSTALL}" -eq 0 ] ; then	# If not over install, volume is new. So delete it
@@ -287,3 +286,31 @@ function on_unexpected_installer_quit(){
 	deactivate_and_close
 	echo "...The new logical volume has been deleted. You can retry Kaiten-yaki again." 
 }
+
+
+# ******************************************************************************* 
+#              Check whether given signaure is in the system information
+# ******************************************************************************* 
+function distribution_check(){
+	if ! uname -a | grep "${DISTRIBUTIONSIGNATURE}" -i > /dev/null  ; then	#  Signature is not found in the OS name.
+		echo "*******************************************************************************"
+		uname -a
+		cat <<- HEREDOC 
+		*******************************************************************************
+		This system seems to be not $DISTRIBUTIONNAME, while this script is dediated to the $DISTRIBUTIONNAME.
+		Are you sure you want to run this script? [Y/N]
+		HEREDOC
+		read -r YESNO
+		if [ "${YESNO}" != "Y" ] && [ "${YESNO}" != "y" ] ; then
+			cat <<- HEREDOC 
+
+			...Installation process terminated..
+			HEREDOC
+			return 1 # with error status
+		fi	# if YES
+
+	fi # Distribution check
+
+	# no error
+	return 0
+}
\ No newline at end of file
diff --git a/script/ubuntu-kaiten-yaki.sh b/script/ubuntu-kaiten-yaki.sh
index 2207d67..27ef8a6 100644
--- a/script/ubuntu-kaiten-yaki.sh
+++ b/script/ubuntu-kaiten-yaki.sh
@@ -4,7 +4,7 @@
 	# Load configuration parameter
 	source ./config.sh
 
-	# Load functions
+	# Load common functions
 	source ./lib.sh
 
 function main() {
@@ -12,30 +12,20 @@ function main() {
 	# This is the mount point of the install target. 
 	export TARGETMOUNTPOINT="/target"
 
-	# Distribution check
-	if ! uname -a | grep ubuntu -i > /dev/null  ; then	# "Ubuntu" is not found in the OS name.
-		echo "*******************************************************************************"
-		uname -a
-		cat <<- HEREDOC 
-		*******************************************************************************
-		This system seems to be not Ubuntu, while this script is dediated to the Ubuntu.
-		Are you sure you want to run this script? [Y/N]
-		HEREDOC
-		read -r YESNO
-		if [ "${YESNO}" != "Y" ] && [ "${YESNO}" != "y" ] ; then
-			cat <<- HEREDOC 
-
-			...Installation process terminated..
-			HEREDOC
-			return 1 # with error status
-		fi	# if YES
-
-	fi # Distribution check
 
 	# ******************************************************************************* 
 	#                                Confirmation before installation 
 	# ******************************************************************************* 
 
+	# parameters for distribution check
+	export DISTRIBUTIONSIGNATURE="ubuntu"
+	export DISTRIBUTIONNAME="Ubuntu"
+
+	# Check whetehr given signature exist or not
+	if ! distribution_check ; then
+		return 1 # with error status
+	fi
+
 	# Common part of the parameter confirmation
 	if ! confirmation ; then
 		return 1 # with error status
diff --git a/script/void-kaiten-yaki.sh b/script/void-kaiten-yaki.sh
index a089463..4af9fea 100644
--- a/script/void-kaiten-yaki.sh
+++ b/script/void-kaiten-yaki.sh
@@ -4,38 +4,28 @@
 	# Load configuration parameter
 	source ./config.sh
 
-	# Load functions
+	# Load common functions
 	source ./lib.sh
 
 function main() {
 
 	# This is the mount point of the install target. 
 	export TARGETMOUNTPOINT="/mnt/target"
-
-	# Distribution check
-	if ! uname -a | grep void -i > /dev/null ; then	# "Void" is not found in the OS name.
-		echo "*******************************************************************************"
-		uname -a
-		cat <<- HEREDOC 
-		*******************************************************************************
-		This system seems to be not Void Linux, while this script is dediated to the Void Linux.
-		Are you sure you want to run this script? [Y/N]
-		HEREDOC
-		read -r YESNO
-		if [ "${YESNO}" != "Y" ] && [ "${YESNO}" != "y" ] ; then
-			cat <<- HEREDOC 
-
-			...Installation process terminated..
-			HEREDOC
-			return 1 # with error status
-		fi	# if YES
-
-	fi # Distribution check
+	
 
 	# ******************************************************************************* 
 	#                                Confirmation before installation 
 	# ******************************************************************************* 
 
+	# parameters for distribution check
+	export DISTRIBUTIONSIGNATURE="void"
+	export DISTRIBUTIONNAME="Void Linux"
+
+	# Check whetehr given signature exist or not
+	if ! distribution_check ; then
+		return 1 # with error status
+	fi
+
 	# Common part of the parameter confirmation
 	if ! confirmation ; then
 		return 1 # with error status