//Workign OK Payment.UI.Windows.Forms.PaymentForm loForm = new PaymentForm(new object[] { JK.Payment.Enums.TxnType.Sale, salesBO.SaleNo, salesBO.Total }); loForm.ShowDialog(); loForm.Dispose(); //Workign OK loForm = (PaymentForm)Activator.CreateInstance(Type.GetType("JK.Payment.UI.Windows.Forms.PaymentForm")); loForm.ShowDialog(); loForm.Dispose(); //NOT Workign OK loForm = (PaymentForm) Activator.CreateInstance(Type.GetType("JK.Payment.UI.Windows.Forms.PaymentForm"), new object[] { JK.Payment.Enums.TxnType.Sale, salesBO.SaleNo, salesBO.Total }); loForm.ShowDialog(); loForm.Dispose();Please advice