Ошибка в добавлении данных в БД

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;
 
namespace Autoservice
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }
 
        private void button1_Click(object sender, EventArgs e)
        {
            this.Close();
        }
 
        public void Form2_Load(object sender, EventArgs e)
        {
            // TODO: данная строка кода позволяет загрузить данные в таблицу "autoserviceDataSet.Customers". При необходимости она может быть перемещена или удалена.
            this.customersTableAdapter.Fill(this.autoserviceDataSet.Customers);
            SqlConnection con = new SqlConnection();
            con.ConnectionString = @"Data Source=VOVSANUCH-ПК\SQLEXPRESS;Initial Catalog=autoservice;Integrated Security=True";
            con.Open();
 
            SqlDataAdapter da = new SqlDataAdapter("select * from Customers", con);
            //SqlCommandBuilder cb = new SqlCommandBuilder(da);
 
            DataSet ds = new DataSet();
            da.Fill(ds, "Customers");
 
            dataGridView1.DataSource = ds.Tables[0];
        }
 
        public void button2_Click(object sender, EventArgs e)
        {
            //Form3 newForm = new Form3();
            ////this.Hide();
            //newForm.Show();
            SqlConnection con = new SqlConnection();
            con.ConnectionString = @"Data Source=VOVSANUCH-ПК\SQLEXPRESS;Initial Catalog=autoservice;Integrated Security=True";
            con.Open();
            SqlDataAdapter insert = new SqlDataAdapter("insert INTO Customers (name, phone, VIN, brand, model, year, produced_work) VALUES (" + Convert.ToString(nametxt.Text) + ",'" + phonetxt.Text + "','" + VINtxt.Text + "','"+ brandtxt.Text +"','"+ modeltxt.Text +"','"+ yeartxt.Text +"','"+ produced_worktxt.Text +"')", con);
            DataSet ds = new DataSet();
            insert.Fill(ds, "Customers");
            SqlDataAdapter da = new SqlDataAdapter("select * from Customers", con);
            //button2.Enabled = false;
            da.Fill(ds, "Customers");
            dataGridView1.DataSource = ds.Tables[0];
 
            
 
        }

System.Data.SqlClient.SqlException не обработано
  HResult=-2146232060
  Message=Недопустимое имя столбца "лоорло".
  Source=.Net SqlClient Data Provider
  ErrorCode=-2146232060
  Class=16
  LineNumber=1
  Number=207
  Procedure=""
  Server=VOVSANUCH-ПК\SQLEXPRESS
  State=1
  StackTrace:
       в System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
       в System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
       в System.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady)
       в System.Data.SqlClient.SqlDataReader.TryConsumeMetaData()
       в System.Data.SqlClient.SqlDataReader.get_MetaData()
       в System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString)
       в System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async, Int32 timeout, Task& task, Boolean asyncWrite)
       в System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, TaskCompletionSource`1 completion, Int32 timeout, Task& task, Boolean asyncWrite)
       в System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method)
       в System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method)
       в System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior)
       в System.Data.Common.DbCommand.System.Data.IDbCommand.ExecuteReader(CommandBehavior behavior)
       в System.Data.Common.DbDataAdapter.FillInternal(DataSet dataset, DataTable[] datatables, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
       в System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
       в System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, String srcTable)
       в Autoservice.Form2.button2_Click(Object sender, EventArgs e) в c:\Users\vovsanuch\Documents\Visual Studio 2012\Projects\Autoservice\Autoservice\Form2.cs:строка 64
       в System.Windows.Forms.Button.OnMouseUp(MouseEventArgs mevent)
       в System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
       в System.Windows.Forms.Control.WndProc(Message& m)
       в System.Windows.Forms.ButtonBase.WndProc(Message& m)
       в System.Windows.Forms.Button.WndProc(Message& m)
       в System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
       в System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
       в System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
       в System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
       в System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
       в Autoservice.Program.Main() в c:\Users\vovsanuch\Documents\Visual Studio 2012\Projects\Autoservice\Autoservice\Program.cs:строка 18
       в System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       в Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       в System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       в System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       в System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       в System.Threading.ThreadHelper.ThreadStart()
  InnerException: