更新一下問題

Panel1

Panel2

aspx

<!-- 輸入舊密碼 -->
<asp:Panel ID="Panel1" runat="server" defaultbutton="Button1">
  <table style="width:100%;text-align:center;" border='1'>
    <tr>
      <td><asp:Label ID="Label1" runat="server" Text="員工編號："></asp:Label></td>
      <td><asp:TextBox ID="TextBox1" runat="server" ReadOnly="True"></asp:TextBox></td>
      <td rowspan="3" class="auto-style2"><asp:Button ID="Button1" runat="server" Text="立即變更密碼" OnClick="Button1_Click" /></td>
    </tr>
    <tr>
      <td><asp:Label ID="Label2" runat="server" Text="員工姓名："></asp:Label></td>
      <td WORD-WRAP: break-word><asp:TextBox ID="TextBox2" runat="server" ReadOnly="True"></asp:TextBox></td>
    </tr>
    <tr>
      <td class="auto-style1"><asp:Label ID="Label3" runat="server" Text="輸入舊密碼："></asp:Label></td>
      <td WORD-WRAP: break-word class="auto-style1"><asp:TextBox ID="TextBox3" runat="server"  TextMode="Password"></asp:TextBox></td>
    </tr>
  </table>
</asp:Panel>
<!-- End輸入舊密碼 -->

<!-- 輸入新密碼 -->
<asp:Panel ID="Panel2" runat="server">
  <asp:DetailsView ID="DetailsView1" runat="server" Height="50px" DataSourceID="SqlDataSourceEmp" AutoGenerateRows="False" DataKeyNames="Emp_Num" OnItemUpdating="DetailsView1_ItemUpdating" OnItemUpdated="DetailsView1_ItemUpdated" Width="100%">
	<Fields>
		<asp:BoundField DataField="Emp_Num" HeaderText="員工編號" SortExpression="Emp_Num" ReadOnly="True" >
			<HeaderStyle Width="100%" /><ItemStyle Width="100%" />
		</asp:BoundField>
		<asp:BoundField DataField="Emp_CnName" HeaderText="員工姓名" SortExpression="Emp_CnName" ReadOnly="True" />
		<asp:BoundField DataField="Emp_Dep" HeaderText="部門/單位" SortExpression="Emp_Dep" ReadOnly="True" />
		<asp:BoundField DataField="Emp_Title" HeaderText="職稱" SortExpression="Emp_Title" ReadOnly="True" />
		<asp:BoundField DataField="Emp_Title_Num" HeaderText="系統預設職等" SortExpression="Emp_Title_Num" ReadOnly="True" />
		<asp:BoundField DataField="Emp_Supervisor" HeaderText="直屬主管員編" SortExpression="Emp_Supervisor" ReadOnly="True" />
		<asp:BoundField DataField="Emp_Mail" HeaderText="帳號/Mail" SortExpression="Emp_Mail" ReadOnly="True" />
		<asp:TemplateField HeaderText="密碼" SortExpression="Emp_PW">
			<EditItemTemplate>
				<asp:Label ID="Label4" runat="server" Text="輸入新密碼："></asp:Label>
				<asp:TextBox ID="TextBox1" runat="server" TextMode="Password" Text='<%# Bind("Emp_PW") %>'></asp:TextBox>
				<br />
				<asp:Label ID="Label5" runat="server" Text="再輸入一次新密碼："></asp:Label>
				<br />
				<asp:TextBox ID="TextBox4" runat="server" TextMode="Password"></asp:TextBox>
			</EditItemTemplate>
			<InsertItemTemplate>
				<asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("Emp_PW") %>' ></asp:TextBox>
			</InsertItemTemplate>
			<ItemTemplate>
				<asp:Label ID="Label1" runat="server" Text='<%# Bind("Emp_PW") %>' Visible="False"></asp:Label>
				<asp:Label ID="Label6" runat="server" Text="********"></asp:Label>
			</ItemTemplate>
		</asp:TemplateField>
		<asp:TemplateField ShowHeader="False">
			<EditItemTemplate>
				<asp:Button ID="Button1" runat="server" CausesValidation="True" CommandName="Update" Text="更新" />
				 <asp:Button ID="Button2" runat="server" CausesValidation="False" CommandName="Cancel" Text="取消" OnClick="Button2_Click" />
			</EditItemTemplate>
			<ItemTemplate>
				<asp:Button ID="Button1" runat="server" CausesValidation="False" CommandName="Edit" Text="編輯" />
			</ItemTemplate>
		</asp:TemplateField>
	</Fields>
  </asp:DetailsView>
</asp:Panel>
<!-- End輸入新密碼 -->

cs

protected void Page_Load(object sender, EventArgs e)
{
	DefenseLogin(); //檢查是否登入
	string struNum = (string)(Session["u_Num"]);	//登入工號
	string uName = (string)(Session["u_Name"]);	//登入名稱
	var value = ((Label)User_Name.FindControl("LoginInfo"));
	value.Text = uName;		//LoginInfo
	TextBox1.Text = struNum;
	TextBox2.Text = uName;
	DetailsView1.Visible = false;
}

protected void Button1_Click(object sender, EventArgs e)
{
  string TB1 = TextBox1.Text; //已登入員工編號
  string TB3 = TextBox3.Text; //舊密碼
  SqlConnection myConn = new SqlConnection(WebConfigurationManager.ConnectionStrings["SqlConnStr"].ConnectionString.ToString());
  myConn.Open(); //打開連接
  String strSQL =
  @"
    select Emp_Num, Emp_PW from emp where Emp_Num = @Emp_Num
  ";
  SqlCommand myCommand = new SqlCommand(strSQL, myConn); 
  myCommand.Parameters.AddWithValue("@Emp_Num", TB1.ToString());
  SqlDataReader myDataReader = null;
  myDataReader = myCommand.ExecuteReader();  
  try
  {
    while (myDataReader.Read())   
    {
      if (myDataReader["Emp_Num"].ToString() == TB1.ToString() && myDataReader["Emp_PW"].ToString() == TB3.ToString())
      {
        Response.Write("<script>alert(\"請於1分鐘內修改密碼！\")</script>");
        DetailsView1.Visible = true;
        s_emp.Visible = false;
        DetailsView1.ChangeMode(DetailsViewMode.Edit);
      }
      else
      {
        Response.Write("<script>alert(\"密碼錯誤，請注意大小寫！\")</script>");
        return;
      }
    }
  }
  catch (Exception ex)
  {
    Response.Write("錯誤訊息=" + ex.ToString());
    Response.Write("<script>alert(\"系統出錯，請聯絡系統管理員！\")</script>");
  }
  finally
  {
    if (myDataReader != null)
    {
      myCommand.Cancel();  
      myDataReader.Close();
    }
    if (myConn.State == ConnectionState.Open)
    {
      myConn.Close();
      myConn.Dispose();
    }
  }
}

protected void DetailsView1_ItemUpdating(object sender, DetailsViewUpdateEventArgs e)
{
	TextBox TB1 = (TextBox)DetailsView1.FindControl("TextBox1"); //更新密碼確認TB1
	TextBox TB4 = (TextBox)DetailsView1.FindControl("TextBox4"); //更新密碼確認TB4
	Button BTN1 = (Button)DetailsView1.FindControl("Button1"); //更新按鈕
	if (TB1.Text != TB4.Text)
	{
		Response.Write("<script>alert(\"密碼更新失敗 \\r 請確認兩次新密碼是否相同！\");history.go(-1);</script>");
		e.Cancel = true;
	}
	else
	{
		Response.Write("<script>alert(\"密碼變更為：[" + TB1.Text.ToString() + "] \\r 請使用新密碼登入 \");location.href='../Login.aspx';</script>");
	}
	TB1.Attributes.Add("onkeydown", "if (event.keyCode==13) { document.getElementById('" + BTN1.ClientID + "').click();return true; }");
	TB4.Attributes.Add("onkeydown", "if (event.keyCode==13) { document.getElementById('" + BTN1.ClientID + "').click();return true; }");
}

我有兩個Panel
主要是要做defaultbutton
Panel1的沒問題
但Panel2該如何取得DetailsView樣板模式內的btn呢?
如下Panel2的defaultbutton="????????"
謝謝

Panel1

<asp:Panel ID="Panel1" runat="server" defaultbutton="Button1">
  <table>
    <tr>
      <td><asp:TextBox ID="TextBox1" runat="server"></asp:TextBox></td>
      <td><asp:Button ID="Button1" runat="server" Text="變更" /></td>
    </tr>
    <tr>
      <td><asp:TextBox ID="TextBox2" runat="server"></asp:TextBox></td>
    </tr>
    <tr>
      <td><asp:TextBox ID="TextBox3" runat="server"></asp:TextBox></td>
    </tr>
  </table>
</asp:Panel>

Panel2

<asp:Panel ID="Panel2" runat="server" defaultbutton="????????">
   <asp:DetailsView ID="DetailsView1" runat="server" " 
	...
	...
	...
   </asp:DetailsView>
</asp:Panel>