First create solution

Nuvolar.Module.CSharp/BusinessObjects/CostPlannerRows.bo.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Nuvolar.Module.BusinessObjects
+{
+    public partial class CostPlannerRows
+    {
+        protected override void OnSaving()
+        {
+            base.OnSaving();
+        }
+        protected override void OnChanged(string propertyName, object oldValue, object newValue)
+        {
+            base.OnChanged(propertyName, oldValue, newValue);
+            if (propertyName == "QTT"||propertyName== "PriceInHUF" || propertyName== "PriceOutHUF")
+            {
+                this.AmountInHUF = this.QTT * this.PriceInHUF;
+                this.AmountOutHUF = this.QTT * this.PriceOutHUF;
+            }
+        }
+    }
+}