asp.net email validator

asp: TextBox ID="email" runat="server" >
asp: RequiredFieldValidator ID="reqEmail" runat="server" ControlToValidate="email" ErrorMessage=""/>
asp: RegularExpressionValidator ID="reqAuthEmail" runat="server" ControlToValidate="email" ValidationExpression="^[\w-\.]+@([\w-]+\.)+[\w-]{2,3}$" ErrorMessage="" />