<select id="s6" multiple="multiple">
<asp:Repeater ID="rpl_dept" runat="server" 
                    onitemdatabound="rpl_dept_ItemDataBound">
<ItemTemplate>
<optgroup label="<%#Eval("Name") %>">
<asp:Repeater ID="rpl_user" runat="server">
<ItemTemplate>
<option><%#Eval("Name")%></option>
</ItemTemplate>
</asp:Repeater>
</optgroup>
</ItemTemplate>
</asp:Repeater>
</select>       

   protected void rpl_bind()
        {
            com.hmby.BLL.Depts dept = new com.hmby.BLL.Depts();
string strWhere = "";
            DataTable dt = new DataTable();
            dt = dept.GetList(strWhere).Tables[0];
if (dt.Rows.Count > 0)
            {
this.rpl_dept.DataSource = dt;
this.rpl_dept.DataBind();
            }
         }

protected void rpl_dept_ItemDataBound(object sender, RepeaterItemEventArgs e)
         {
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
             {
                 Repeater rep = e.Item.FindControl("rpl_user") as Repeater;//找到里层的repeater对象
                 DataRowView rowv = (DataRowView)e.Item.DataItem;//找到分类Repeater关联的数据项 
                 int deptId = Convert.ToInt32(rowv["Id"]); //获取填充子类的id 
                 DataTable dt = new DataTable();
                 com.hmby.BLL.Users user = new com.hmby.BLL.Users();
string strWhere = " DeptId=" + deptId;
                 dt = user.GetList(strWhere).Tables[0]; ;
if (dt.Rows.Count > 0)
                 {
                     rep.DataSource = dt;
                     rep.DataBind();
                 }

             }

         }

<asp:Repeater ID="rpl_mParent" runat="server"
                        onitemdatabound="rpl_mParent_ItemDataBound">
    <ItemTemplate>
        <tr>
            <td style="vertical-align:top;background-color:#ffa !important;">
            <input type="checkbox" )%></label>
        </td></tr>
        </ItemTemplate>
        </asp:Repeater>
    </ItemTemplate>
    </asp:Repeater>

for (int i=0;i<this.rpl_mParent.Items.Count;i++)
            {
                HtmlInputCheckBox cbox_p = (HtmlInputCheckBox)rpl_mParent.Items[i].FindControl("cbox_p");
if (cbox_p.Checked)
                { 
//选中了checkbox_p
                    JsUtil.Alert(this, "p");
                }
                Repeater rplChild = (Repeater)rpl_mParent.Items[i].FindControl("rpl_mChild");
string c = "";
for (int j=0;j<rplChild.Items.Count;j++)
                {
                    HtmlInputCheckBox cbox_c = (HtmlInputCheckBox)rplChild.Items[j].FindControl("cbox_c");
if (cbox_c.Checked)
                    { 
//选中了checkbox_c
                        c += cbox_c.Value + ",";
                    }
                }
                JsUtil.Alert(this, c);
            }