AJAX :: Accordion Header Click Event

I have an accordion control with header and content templates. I am binding this control at pageload but, due to the page load time i want to bind the headers only to the accordion in the pageload and when the user click on the header after pageload i want to bind the content to the accordion. I have succeded to add an event to the header but when i clicked on the header page postback is happening even the entire accordion in the updatepanel. Here is the code to ref.

<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Accordion ID="Accordion1" runat="server" Width="800px">
<HeaderTemplate>
<asp:LinkButton ID="LinkButton1" runat="server" Width="97%" CommandName='<%#Eval("name")%>' OnCommand="getdata"><%#Eval("name")%>
<asp:Label ID="Label1" runat="server" Text='<%#Eval("name")%>'></asp:Label>
</asp:LinkButton>
</HeaderTemplate>
<ContentTemplate>
<asp:Label ID="Label2" runat="server" Text=""></asp:Label>
</ContentTemplate>
</asp:Accordion>
</ContentTemplate>
</asp:UpdatePanel>

The getdata method is executing when i clicked on the headerhere is the cs code

public partial class WebForm1 : System.Web.UI.Page
{
string[] names = { "Brand", "Success", "Navigation" };
int[] value = { 10, 20, 30 };
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
DataTable dt = new DataTable();
DataColumn dc1 = new DataColumn("name");
DataColumn dc2 = new DataColumn("value");
dt.Columns.Add(dc1);
dt.Columns.Add(dc2);
for (int i = 0; i < 3; i++)
{
DataRow dr = dt.NewRow();
dr["name"] = names[i].ToString();
dr["value"] = value[i].ToString();
dt.Rows.Add(dr);
}
Accordion1.DataSource = dt.DefaultView;
Accordion1.DataBind();
}
}
protected void getdata(object sender, CommandEventArgs e)
{
if (e.CommandName == "Brand")
{
((Label)Accordion1.Panes[0].FindControl("Label2")).Text = value[0].ToString();
}
if (e.CommandName == "Success")
{
((Label)Accordion1.Panes[1].FindControl("Label2")).Text = value[1].ToString();
}
if (e.CommandName == "Navigation")
{
((Label)Accordion1.Panes[2].FindControl("Label2")).Text = value[2].ToString();
}
}
}

I need to eliminate the postback from this page. I tried it only accordion on the page then it is working fine(with out postback) but when integrated it with the other code in which again am having some ajax functionality then the post back is occurring.