Selection in ASP.Net GridView control

string constr = ConfigurationManager.ConnectionStrings["narayanaConnectionString"].ConnectionString;
    SqlConnection cn;
    protected void Page_Load(object sender, EventArgs e)
    {
        LinkButton lb;
        if (!IsPostBack)
        {
            
            bind();
            
        }
        
        for (int i = 0; i < GridView1.Rows.Count; i++)
        {
            lb = new LinkButton();
            
            lb.ID = "LinkButton" + i.ToString();
            lb.Text = ""+GridView1.Rows[i].Cells[0].Text;
            lb.Font.Name = "Verdana";
            PlaceHolder1.Controls.Add(lb);
            lb.Click +=new EventHandler(lb_Click);
        }
    }
    protected void lb_Click(object sender, EventArgs e)
    {
        LinkButton lb = (LinkButton)sender;
        int i=Convert.ToInt16 (lb.Text );
        GridView1.SelectedIndex = i - 1;
        GridView1.SelectedRow.Cells[0].Focus();
        
        GridView1.SelectedRow.Cells[0].BackColor = Color.Red;
    }
    public void bind()
    {
        cn = new SqlConnection(constr);
        SqlDataAdapter da = new SqlDataAdapter("select * from student", cn);
        DataSet ds = new DataSet();
        da.Fill(ds);
        GridView1.DataSource = ds;
        GridView1.DataBind();
    }