Validate Money Currency format in ASP.Net TextBox using Validators

<asp:TextBox ID="txt_Amount" runat="server"></asp:TextBox>

    <asp:RegularExpressionValidator ID="RegularExpressionValidator10" runat="server"

        ControlToValidate="txt_Amount" ErrorMessage="Please enter only numbers like 1000 or 1000.00"

        ValidationExpression="^\d+(\.\d\d)?$"></asp:RegularExpressionValidator>