كود الحفظ فى داتا جريد فيو

انا استخدم هذة الدالة فى الحفظ والتعديل والاضافة

Public Class Class1
    Public Shared sqlconn As New SqlConnection
    'دوال بناء اوامر الحفظ والحذف والتعديل
    Public Function SQLEXICUTE(ByVal SQLstatment As String) As Boolean
        Try
            Dim cmd As New SqlCommand
            cmd.CommandText = SQLstatment
            sqlconn.Open()
            cmd.Connection = sqlconn
            cmd.ExecuteNonQuery()
            Return True
        Catch ex As Exception
            Return False
            MsgBox(ex.Message)
        Finally
            sqlconn.Close()
        End Try
    End Function

اريد معرفة ما هو الخطاء فى كود الحفظ من الداتا جريد الى قاعدة بيانات اس كيو ال

        Dim i As Integer
        Dim row As DataGridViewRow = AddDGV.Rows(i)

        Dim coditem As DataGridViewTextBoxCell = row.Cells(0)
        Dim nameitem As DataGridViewTextBoxCell = row.Cells(1)
        Dim quntity As DataGridViewTextBoxCell = row.Cells(2)
        Dim unitprice As DataGridViewTextBoxCell = row.Cells(3)
        Dim total As DataGridViewTextBoxCell = row.Cells(4)
        Dim Discount As DataGridViewTextBoxCell = row.Cells(5)
        Dim nettotal As DataGridViewTextBoxCell = row.Cells(6)
        'Dim Invoice_number As String = "1zQQ234"    ' Change that to correct invoice_number                                                                                                                                       
        Dim saveok As Boolean = winclass.SQLEXICUTE(" insert into transactions (coditem,nameitem,quntity,unitprice,total,Discount ,nettotal) values (" & coditem.Value & ",'" & nameitem.Value & "'," & quntity.Value & "," & unitprice.Value & "," & total.Value & "," & Discount.Value & "," & nettotal.Value & ")")
        If saveok = True Then
            MsgBox("تمت عملية الحفظ بنجاج", MsgBoxStyle.Exclamation, "تأكيد عملية الحفظ")
                    End If