CustomValidator message doesnt show up
<p>I've a CustomValidator and I defined every possible parameter of it:</p>

<pre><code>&lt;asp:CustomValidator ID="custom" runat="server" Text="*" ErrorMessage="This email address is already registered" ControlToValidate="txtEmail" OnServerValidate="isExist" Display="None" ValidationGroup="valRegister"&gt;&lt;/asp:CustomValidator&gt;
</code></pre>

<p>PS: I've a RequiredFieldValidator for same textbox and I dont want to check empty value.</p>

<p>Here are other objects of the form:</p>

<pre><code>&lt;div class="row"&gt;&lt;asp:Label runat="server" Text="Email" AssociatedControlID="txtEmail"&gt;&lt;/asp:Label&gt;&lt;asp:RequiredFieldValidator runat="server" ErrorMessage="Please enter your email" Text="*" ControlToValidate="txtEmail"&gt;&lt;/asp:RequiredFieldValidator&gt;&lt;asp:TextBox ID="txtEmail" runat="server" CssClass="inpBox"&gt;&lt;/asp:TextBox&gt;&lt;/div&gt;

&lt;asp:Button runat="server" Text="Register" CssClass="btn" OnClick="register_member" CausesValidation="true" ValidationGroup="valRegister" /&gt;

&lt;asp:ValidationSummary ID="validationSummary" runat="server" ShowMessageBox="true" ShowSummary="false" ValidationGroup="valRegister" /&gt;
</code></pre>

<hr>

<pre><code>protected void isExist(object sender, ServerValidateEventArgs args){
if (cre.member.isExist(args.Value)){
    args.IsValid = false;
} else {
    args.IsValid = true;
}
</code></pre>

<p>}</p>

<p>When I put an email already exist in the db table * appears on the form, but the error message doesnt show up. I tried all display options for custom error but no luck.</p>

<p>Thanks.</p>
