Image button click event in datalist not firing

问题:

I have an imagebutton which is in a datalist. Onclick, the event for the image button is not firing. How can I get it to fire?

<asp:DataList ID="datalistsoru" runat="server" 
        BorderColor="#CCCCCC" BorderStyle="Solid" BorderWidth="1px" >
        <ItemTemplate>
 <asp:ImageButton ID="ImageButton1" runat="server"
        OnClick="ImageButton1_Click"  ImageUrl="~/resimler/yukariok.jpg" ToolTip="Oyu Arttır" />
 </ItemTemplate>

protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
{
    Response.Redirect("Default.aspx");
}