How do you validate phone number in asp.net?

How do you validate phone number in asp.net?

I need to validate phone number that allows numeric and symbols + - () how
can i do so in asp.net?
<asp:TextBox ID="TxtNo" runat="server"></asp:TextBox>
<asp:RegularExpressionValidator ID="RegularExpressionValidator2"
runat="server" ErrorMessage="Enter valid Phone number"
ControlToValidate="TxtNo" ></asp:RegularExpressionValidator>