dynamically controls generation
for (int j = 1; j <= Convert.ToInt32(txtNoOFControl.text); j++)
{
TextBox txt = new TextBox();
txt.Size = new Size(34, 24);
txt.Location = new Point(((j % 20) * 34), (j / 20 * 34));
txt.Text = j.ToString();
txt.TabIndex = j;
txt.Visible = true;
this.Controls.Add(txt);
}