datagGridView Problem

[jamshed ahmed]

hellow and and hi iam developing billing system in which i have used gridview control with three columns named Description,qty,price and total code given below it works fine but problem is when i edit any cell of datagrid a new row inserted automatically is there any property or way by the mean of which new row is inserted only when enter key is pressed "DgvBill.Rows.Add()" by this code new row will be inserted and reason i want to add new row by pressing enter key is only because of handling empty cell if any required cell is empty then it should keep focus on this row only this simple what i want thxxx

Private Sub DgvBill_KeyUp(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles DgvBill.KeyUp
        Try

            Dim qty As Integer = 0
            Dim price As Integer = 0
            Dim total As Integer = 0
            Dim j As Integer = 0

            If e.KeyCode = Keys.Enter Then

                For j = 0 To DgvBill.RowCount - 2
                    If DgvBill.Item("ClmQty", j).Value = "" Then
                        MsgBox("PLEASE ENTER QTY VALUE")
                        DgvBill.CurrentCell = DgvBill.Item("ClmQty", j)
                        DgvBill.BeginEdit(True)
                        Return
                    End If

                    If DgvBill.Item("ClmPrice", j).Value = "" Then
                        MsgBox("PLEASE ENTER PRICE VALUE")
                        DgvBill.CurrentCell = DgvBill.Item("ClmPrice", j)
                        DgvBill.BeginEdit(True)
                        Return
                    End If

                    qty = CInt(DgvBill.Item("ClmQty", j).Value.ToString)
                    price = CInt(DgvBill.Item("ClmPrice", j).Value.ToString)
                    total = qty * price
                    DgvBill.Item("ClmTotal", j).Value = total


                Next

            End If

        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
    End Sub