update processing,customer and staff

lib/pages/rates/cargo_editor.dart

@@ -105,6 +105,10 @@ class _CargoEditorState extends State<CargoEditor> {
   }
 
   _save() async {
+    if (_rateController.text == "") {
+      showMsgDialog(context, "Error", "Please insert rate");
+      return;
+    }
     setState(() {
       _isLoading = true;
     });

lib/pages/rates/custom_editor.dart

@@ -118,6 +118,16 @@ class _CustomEditorState extends State<CustomEditor> {
   }
 
   _save() async {
+    if (_feeController.text == "") {
+      showMsgDialog(context, "Error", "Please insert fee");
+      return;
+    }
+
+    if (_shipmentRateController.text == "") {
+      showMsgDialog(context, "Error", "Please insert shipment rate");
+      return;
+    }
+
     setState(() {
       _isLoading = true;
     });

lib/pages/rates/discount_by_weight_editor.dart

@@ -107,6 +107,16 @@ class _DiscountByWeightEditorState extends State<DiscountByWeightEditor> {
   }
 
   _save() async {
+    if (_weightController.text == "") {
+      showMsgDialog(context, "Error", "Please insert weight");
+      return;
+    }
+
+    if (_discountController.text == "") {
+      showMsgDialog(context, "Error", "Please insert discount rate");
+      return;
+    }
+
     setState(() {
       _isLoading = true;
     });