Asp.net:to call event handler of dynamically generated buttons

i have set enableviewstate property of linkbutton and label to true.also regenrating same buttons on postback in pageload event handler.but m not able to call onclick event handler of linkbutton.can u please tell me what is problem with code?

public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

        List<LinkButton> listOfLinkButton = Session["ListOfLinkButton"] as List<LinkButton>;
        List<Label> listOfLabel = Session["ListOfLabel"] as List<Label>;
        if(listOfLabel!=null && listOfLinkButton!=null)
        {
            for (int i = 0; i < listOfLinkButton.Count; i++)
            {
                PlaceHolder1.Controls.Add(listOfLinkButton[i]);
                PlaceHolder1.Controls.Add(new LiteralControl("<br />"));
                PlaceHolder1.Controls.Add(listOfLabel[i]);
                PlaceHolder1.Controls.Add(new LiteralControl("<br />"));
            }
        }



}



protected void LinkButton_Click(object sender, EventArgs e)
{
    LinkButton linkButton = sender as LinkButton;

    Response.Redirect(linkButton.Attributes["LinkUrl"]);        
}
protected void Button1_Click1(object sender, EventArgs e)
{

    List<LinkButton> listOfLinkButton = new List<LinkButton>();
    List<Label> listOfLabel = new List<Label>();
    Rss rssDocumentObj = RssFileReader.GetRssDocumentData(TextBox1.Text);
    for (int j = 0; j < rssDocumentObj.ListOfChannel.Count; j++)
    {
        LinkButton linkButton = new LinkButton();
        linkButton.ID = "LinkButtonForChannelDynamicInPlaceHolder1Id" + j;
        linkButton.EnableViewState = true;
        linkButton.ForeColor = Color.Blue;
        linkButton.Font.Bold = true;
        linkButton.Font.Size = 18;
        linkButton.Font.Underline = true;
        linkButton.Text = rssDocumentObj.ListOfChannel[j].ChannelTitle.InnerText;
        linkButton.Click += new EventHandler(LinkButton_Click);
        linkButton.Attributes.Add("LinkUrl", rssDocumentObj.ListOfChannel[j].ChannelLink.InnerText);
        linkButton.Attributes.Add("onmouseover", "this.style.color = '#006699'");
        linkButton.Attributes.Add("onmouseout", "this.style.color = '#0000ff'");
        PlaceHolder1.Controls.Add(linkButton);
        listOfLinkButton.Add(linkButton);
        PlaceHolder1.Controls.Add(new LiteralControl("<br />"));
        Label label = new Label();
        label.ID = "LabelForChannelDynamicInPlaceHolder1Id" + j;
        label.EnableViewState = true;
        label.ForeColor = Color.DarkSlateGray;
        label.Text = rssDocumentObj.ListOfChannel[j].ChannelDescription.InnerText;
        PlaceHolder1.Controls.Add(label);
        listOfLabel.Add(label);
        PlaceHolder1.Controls.Add(new LiteralControl("<br />"));

        for (int i = 0; i < rssDocumentObj.ListOfChannel[j].ListOfItem.Count; i++)
        {
            LinkButton linkButtonForItem = new LinkButton();
            linkButtonForItem.ID = "LinkButtonDynamicInPlaceHolder1Id" + j + " " + i;
            linkButtonForItem.EnableViewState = true;
            linkButtonForItem.ForeColor = Color.Blue;
            linkButtonForItem.Font.Bold = true;
            linkButtonForItem.Font.Size = 14;
            linkButtonForItem.Font.Underline = false;
            linkButtonForItem.Text = rssDocumentObj.ListOfChannel[j].ListOfItem[i].ItemTitle.InnerText;
            linkButtonForItem.Click += new EventHandler(LinkButton_Click);
            linkButtonForItem.Attributes.Add("LinkUrl", rssDocumentObj.ListOfChannel[j].ListOfItem[i].ItemLink.InnerText);
            linkButtonForItem.Attributes.Add("onmouseover", "this.style.color = '#006699'");
            linkButtonForItem.Attributes.Add("onmouseout", "this.style.color = '#0000ff'");
            PlaceHolder1.Controls.Add(linkButtonForItem);
            listOfLinkButton.Add(linkButtonForItem);
            PlaceHolder1.Controls.Add(new LiteralControl("<br />"));
            Label labelForItem = new Label();
            labelForItem.ID = "LabelDynamicInPlaceHolder1Id" + i;
            labelForItem.EnableViewState = true;
            labelForItem.ForeColor = Color.DarkGray;
            labelForItem.Text = rssDocumentObj.ListOfChannel[j].ListOfItem[i].ItemDescription.InnerText;
            PlaceHolder1.Controls.Add(labelForItem);
            listOfLabel.Add(labelForItem);
            PlaceHolder1.Controls.Add(new LiteralControl("<br />"));
            Session["ListOfLinkButton"] = listOfLinkButton;
            Session["ListOfLabel"] = listOfLabel;
        }
    }  
}

}