alpha numeric pager issues please help

Question

I have this:

 public partial class Glossario : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        DataSet objDataSet = new DataSet();
        // Read in the XML file
        objDataSet.ReadXml(Server.MapPath("glossary.xml"));

        GridView1.DataSource = objDataSet;
        GridView1.DataBind();

    }

    protected void GridView1_PageIndexChanging(object sender, GridViewPageEventArgs e)
    {
        GridView1.PageIndex = e.NewPageIndex;
    }

    protected void GridView1_DataBound(object sender, EventArgs e)
    {
        SetPaging();
    }

    private void SetPaging()
    {
        GridViewRow row = GridView1.BottomPagerRow;
        int alphaStart = 65;

        for (int i = 1; i < GridView1.PageCount; i++)
        {
            LinkButton btn = new LinkButton();
            btn.CommandName = "Page";
           
            btn.CommandArgument = i.ToString();

            if (i == GridView1.PageIndex + 1)
            {
                btn.BackColor = Color.BlanchedAlmond;
            }

            btn.Text = Convert.ToChar(alphaStart).ToString();
            btn.ToolTip = "Page " + i.ToString();
            alphaStart++;
            PlaceHolder place = row.FindControl("PlaceHolder1") as PlaceHolder;
            place.Controls.Add(btn);

            Label lbl = new Label();
            lbl.Text = " ";
            place.Controls.Add(lbl);
        }
       
    }

}

this is the front end

 <asp:PlaceHolder ID="PlaceHolder" runat="server" />

I don't know what I'm doing wrong. can anyone help.