RegularExpression Email Validation

<asp:TextBox ID="txtEmailID" runat="server" MaxLength="30" Width="140px"></asp:TextBox>

<asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server" 
ErrorMessage="Enter valid Email Id" ControlToValidate="txtEmailID"  SetFocusOnError="true" 
ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*">
</asp:RegularExpressionValidator>