Email validation?

Hello
If I leave the @ out of the email address when completing my contact form, I get a 'The specified string is not in the form required for an e-mail address' error, so I have looked around for something stronger than the code I have such as:
<p><asp:Label ID="Email" runat="server" Text="Email"></asp:Label> <asp:TextBox ID="your_email" runat="server" required></asp:TextBox></p><br /> <asp:RequiredFieldValidator Display="Dynamic" ID="RequiredFieldValidator2" runat="server" ErrorMessage="*" ControlToValidate="your_email" ForeColor="#FF6666"></asp:RequiredFieldValidator> <asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server" ErrorMessage="Please complete the Emai ...