ช่วยดูำ error ให้หน่อยค่ะมันขึ้น ExecuteNonQuery : Connection property has not been initialized.

If con.State = ConnectionState.Open Then con.Close()
        con.Open()

     Dim sqladd As String
       comm = New OleDbCommand
     If con.State = ConnectionState.Open Then con.Close()
     con.Open()
       sqladd = "insert into product(id_pro,id_type,)"
       sqladd &= " values ('" & TextBox1.Text & "',"
       sqladd &= "'" & ComboBox1.Text & "')"
       

       comm = New OleDbCommand
       With comm
           .CommandType = CommandType.Text
           .CommandText = sqladd
           .Connection = con
           .ExecuteNonQuery()
       End With
       MessageBox.Show("บันทึกข้อมูลเรียบร้อยแล้ว", "ยืนยันการบันทึก")

Dim objConn As System.Data.OleDb.OleDbConnection
Dim objCmd As System.Data.OleDb.OleDbCommand
Dim strConnString,strSQL As String

strConnString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source="&Server.MapPath("database/mydatabase.mdb")&";Jet OLEDB:Database Password=;"
objConn = New OleDbConnection(strConnString)
objConn.Open()

strSQL = "INSERT INTO customer (CustomerID,Name,Email,CountryCode,Budget,Used) " & _
"VALUES ('C005','Weerachai Nukitram','[email protected]','TH','2000000','1000000')"

objCmd = New OleDbCommand(strSQL,objConn)

Try
objCmd.ExecuteNonQuery()
Catch ex As Exception
lblText.Text = lblText.Text & "<br> - Record not insert was (" & ex.Message & ")"
End Try


objCmd = Nothing
objConn.Close()
objConn = Nothing