// default button makes postback(for enter key)
 protected void txtSearchItems_TextChanged(object sender, EventArgs e)
 {
     if (!UseJavaScriptForControlAction)
     {
         DataTable dtItems   = (DataTable)Session[("DDlCheckBoxListItemsSN" + ID)];
         string    RowFilter = String.Format(DataTextField + " LIKE '%" + UDFLib.EscapeLikeValue(txtSearchItems.Text) + "%'");
         dtItems.DefaultView.RowFilter = RowFilter;
         CheckBoxListItems.DataSource  = dtItems.DefaultView;
         CheckBoxListItems.DataBind();
         UpdatePanelheckBoxListItems.Update();
     }
 }
    // in use when useSession is true (selection using jquery)
    protected void chkSelectAll_CheckedChanged(object sender, EventArgs e)
    {
        foreach (ListItem liItems in CheckBoxListItems.Items)
        {
            //JIT: JIT/JIBE/9192
            //Mdf By:Nilesh Pawar Mdf on:17/06/2016
            if (!chkSelectAll.Checked && liItems.Selected == false)
            {
                liItems.Selected = chkSelectAll.Checked;
            }

            //End
        }
        UpdatePanelheckBoxListItems.Update();
    }