diff --git a/common/empty.js b/common/empty.js
new file mode 100644
index 0000000..f44d8fd
--- /dev/null
+++ b/common/empty.js
@@ -0,0 +1,12 @@
+function stringIsEmpty(str) {
+	return str === undefined || str === null || str === ''
+}
+
+function stringIsNotEmpty(str) {
+	return !stringIsEmpty(str)
+}
+
+export {
+	stringIsEmpty,
+	stringIsNotEmpty
+}
diff --git a/common/mixin.js b/common/mixin.js
deleted file mode 100644
index b6a4eee..0000000
--- a/common/mixin.js
+++ /dev/null
@@ -1,7 +0,0 @@
-export default {
-    data() {
-        return {
-
-        }
-    }
-}