Regular Expression (Regex) for number with two decimal points in ASP.Net RegularExpression Validator

This way

  <asp:TextBox ID="TextBox1" runat="server" />
    <asp:RegularExpressionValidator ID="Regex1" runat="server" ValidationExpression="(?:\d*\.\d{1,2}|\d+)$" ErrorMessage = "Please enter valid decimal number with 2 decimal places."
        ControlToValidate="TextBox1" />
    <asp:Button Text="Validate" runat="server" />

Regex Ref: http://stackoverflow.com/questions/468655/javascript-decimal-place-restriction-with-regex