Textbox OnkeyPress error

Updated:  I have hard time inserting the block of codes.... :)

Hello experts,
I am writing a class for NumericTextbox that holds only specific keys.... and I run into the weird problem that I can't figure out:
Here is my class:
using System;
using System.IO;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.SessionState;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Globalization;


public class NumericTextBox : TextBox
{
bool allowSpace = false;

// Restricts the entry of characters to digits (including hex), the negative sign,
// the decimal point, and editing keystrokes (backspace).
prote ...