Inserting multiple dynamic textbox values into database using windows form

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C#7.0

I got references for adding dynamic textbox values and storing all the textbox values into the database on single submit button using Asp.net.But now I need the same task to be done in windows form.Can some one help me how to insert all the dynamic textbox values on single click of submit button.(For example:If I add some five rows of text boxes all the five rows should be inserted into database).I am using Windows Application Form,SQl Server and Linq to SQL class.
Note:I am able to insert one row at a time.But I need multiple rows to be inserted into database.

What I have tried:

public partial class Form1 : Form
    {
        List<textbox> textBoxes;
        TextBox tb1;
        TextBox tb2;
        TextBox tb3;
        TextBox tb4;
        ComboBox cm;
        int lbltext = 1;
        int A = 1;
        int i = 0;
        int j = 0;
        public Form1()
        {
            InitializeComponent();
            textBoxes = new List<textbox>();
        }
        //Add Button for adding Dynamic TextBoxes
        private void Button1_Click(object sender, EventArgs e)
        {
            Show(); 
            if (A > 12)
            {
                MessageBox.Show("Cannot insert More than 12 records in a page");
            }
            A += 1;
            lbltext += 1;
        }
        private new void Show()
        {
            i++;
            tb1 = new TextBox()
            {
                Text = (lbltext).ToString() + ".",
                Height = 22,
                Width = 17,
                Left = 9,
                Top = 140 + A * 36,
             // Parent = FormWindowState.Normal,
                Name = "textbox" + i
            };
            i++;
            tb2 = new TextBox
            {
                Height = 22,
                Width = 60,
                Left = 43,
                Top = 140 + A * 36,
                Name ="textbox"+i
            };
            i++;
            tb3 = new TextBox {
                Height = 22,
                Width = 64,
                Left = 122,
                Top = 140 + A * 36,
                Name="textbox"+i
            };
            i++;
            tb4 = new TextBox {
            Height = 22,
            Width = 80,
            Left = 220,
            Top = 140 + A * 36,
            Name ="textbox"+i
            };
            j++;
            cm = new ComboBox();
            cm.Text = "-NONE-";
            cm.Items.Add("-PRESENT-");
            cm.Items.Add("-LEAVE-");
            cm.Items.Add("-HOLIDAY-");
            cm.Left = 358;
            cm.Width = 92;
            cm.Height = 22;
            cm.Name = "ComBoBox" + j;
            cm.Top = 140 + A * 36;
            textBoxes.Add(tb1);
            textBoxes.Add(tb2);
            textBoxes.Add(tb3);
            textBoxes.Add(tb4);
            this.Controls.Add(tb1);
            this.Controls.Add(tb2);
            this.Controls.Add(tb3);
            this.Controls.Add(tb4);
            this.Controls.Add(cm);
        }
       //Submitting values to Database
        private void Button2_Click(object sender, EventArgs e)
        { 
            ExampleDataContext dc = new ExampleDataContext();
            TextBox3 tb = new TextBox3();
            TextBox4 dtb4 = new TextBox4();
            TextBox5 dtb5 = new TextBox5();
            TextBox6 dtb6 = new TextBox6();
            ComboBox2 dcm = new ComboBox2();
            Lable lable = new Lable();
            try
            {   
                    lable.textvalue = lbltext.ToString();
                    //For Storing S.No
                    tb.textvalue = lbltext - 1;
                    tb.HeightValue = tb1.Height;
                    tb.WidthValue = tb1.Width;
                    tb.LeftValue = tb1.Left;
                    tb.TopValue = tb1.Top;
                    tb.name = tb1.Name;
                    select tb.textvalue;
                    dc.TextBox3s.InsertOnSubmit(tb);
                    dc.SubmitChanges();
                    //For Storing Id
                    dtb4.textvalue = tb2.Text;
                    dtb4.HeightValue = tb2.Height;
                    dtb4.WidthValue = tb2.Width;
                    dtb4.LeftValue = tb2.Left;
                    dtb4.TopValue = tb2.Top;
                    dtb4.name = tb2.Name;
                    dc.TextBox4s.InsertOnSubmit(dtb4);
                    dc.SubmitChanges();
                    //For Storing Name
                    dtb5.textvalue = tb3.Text;
                    dtb5.HeightValue = tb3.Height;
                    dtb5.WidthValue = tb3.Width;
                    dtb5.LeftValue = tb3.Left;
                    dtb5.TopValue = tb3.Top;
                    dtb5.name = tb3.Name;
                    dc.TextBox5s.InsertOnSubmit(dtb5);
                    dc.SubmitChanges();
                    //For Storing Designation
                    dtb6.textvalue = tb4.Text;
                    dtb6.HeightValue = tb4.Height;
                    dtb6.WidthValue = tb4.Width;
                    dtb6.LeftValue = tb4.Left;
                    dtb6.TopValue = tb4.Top;
                    dtb6.name = tb4.Name;
                    dc.TextBox6s.InsertOnSubmit(dtb6);
                    dc.SubmitChanges();
                    //For Storing Attendence ComboBox
                    dcm.LeftValue = cm.Left;
                    dcm.HeightValue = cm.Height;
                    dcm.TopValue = cm.Top;
                    dcm.WidthValue = cm.Width;
                    dcm.textvalue = cm.Text;
                    dcm.name = cm.Name;
                    dc.ComboBox2s.InsertOnSubmit(dcm);
                    dc.SubmitChanges();
                    MessageBox.Show("Record inserted successfully");
            }
            catch (Exception ex)
            {
                MessageBox.Show("Record already exists" + ex.Message);
            }
        }
        private void Form1_Load(object sender, EventArgs e)
        {   //For maintaining the names of dynamic textboxes when the form got loaded 
            //for the second time
            this.WindowState = Properties.Settings.Default.F1State;
          
            }
        }