diff --git a/BO/Controllers/croomController.cs b/BO/Controllers/croomController.cs
index 24e70a3..86b95ab 100644
--- a/BO/Controllers/croomController.cs
+++ b/BO/Controllers/croomController.cs
@@ -891,6 +891,10 @@ namespace NP.BO.Controllers
         public ActionResult tax(VMCRoom vm)
         {
             var ht = SetHash(vm, false);
+            if(vm.isexceldown != 1)
+            {
+                vm.stringval11 = null;
+            }
             if (!IsPost())
             {
                 vm.stringval6 = DateTime.Now.ToString("yyyy-MM-01");