Added an error message to the layout switcher

switch-layout

@@ -23,5 +23,7 @@ case ${LAYOUT} in
             [[ -e ~/.screenlayout/${LAYOUT}.sh-after ]] && \
                 sh ~/.screenlayout/${LAYOUT}.sh-after
             echo Switched to ${LAYOUT} layout
+        else
+            echo "${LAYOUT} not available"
         fi
 esac