Validation summary not showing
<p>Why my validation summary not show after i click ligin button in my login control. It supposed to show an error message if i leave it blank in  username n password box right? Can you guys tell me what should i do? Im using a master page. Thank you.</p>

<pre><code>   &lt;asp:Login ID="Login1" runat="server" BackColor="#F7F7DE" BorderColor="#CCCC99" 
                            BorderStyle="Solid" BorderWidth="1px" Font-Names="Verdana" Font-Size="10pt"&gt;
                            &lt;TitleTextStyle BackColor="#6B696B" Font-Bold="True" ForeColor="#FFFFFF" /&gt;
                        &lt;/asp:Login&gt;
                    &lt;/p&gt;
                   &lt;asp:ValidationSummary ID="ValidationSummary1" runat="server" 
    ValidationGroup="Login1" /&gt;
</code></pre>
