全选 全消 多条记录删除(asp.net)

<asp:CheckBox id="chkExport" runat="server" ></asp:CheckBox>
<INPUT id="Hidden1" type="hidden" size="1" name="Hidden1" runat="server" value='<%# DataBinder.Eval(Container.DataItem,"id")%>'>

System.Web.UI.WebControls.CheckBox chkExport;
     if(cmdSelectAll.Text == "全选")
    {
        foreach(RepeaterItem item in Repeater1.Items)
     {
      chkExport = (CheckBox)item.FindControl("chkExport");
      chkExport.Checked =true;
     }

     cmdSelectAll.Text = "全消";
    }
    else
    {
     foreach(RepeaterItem item in Repeater1.Items)
     {
      chkExport = (CheckBox)item.FindControl("chkExport");
     chkExport.Checked = false;
     }
     cmdSelectAll.Text = "全选";
    }

System.Web.UI.WebControls.CheckBox chkExport;
    string sID;
    foreach (RepeaterItem item in Repeater1.Items)
    {

     chkExport = (CheckBox)item.FindControl("chkExport");
     //如果选中了则取值
     if(chkExport.Checked)
     {
      sID=((HtmlInputHidden)item.FindControl("Hidden1")).Value.ToString();
      Response.Write(sID);
     }

    }