>It would be good to see the code in C#.

Okey dokey .... here ya go.

This example has been subclassed from MyTextBox subclass and will need additional tweaking if you want to sub-class from the System.Windows.Forms.TextBox. In particular notice that all the eventhandlers are overridden from the parent class. But other than that minor tweaking, this should work just fine.

	public class MyNumericTextBox : MyTextBox
	{
		#region Declarations
		private int m_DecimalPlaces = 0;
		private decimal m_Maximum = 100;
		private decimal m_Minimum = 0;
		protected char[] AllowedChars = {'1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '-'};
		protected string m_FormatString = "##0";
		private bool m_DisplayDefaultZero = true;
		#endregion

		#region Constructor
		public MyNumericTextBox()
		{
			this.MaxLength = 3;
			this.TextAlign = System.Windows.Forms.HorizontalAlignment.Right;
		}
		#endregion

		#region Methods
		public void SetText(object val)
		{
			if (this.m_Minimum > 0)
			{
				if (val is Decimal)
					this.Text = ((decimal)val).ToString(this.m_FormatString);
			}
			else
			{
				if (val is int)
					this.Text = ((int)val).ToString(this.m_FormatString);
			}
		}
		#endregion

		#region Events
		protected override void FormatHandler(object sender, ConvertEventArgs e)
		{
			if(this.DisplayDefaultZero) 
			{
				if (e.Value == System.DBNull.Value)
					e.Value = (int)0;
			}
			if (e.Value is Decimal && e.DesiredType == typeof(string))
				e.Value = ((decimal)e.Value).ToString(this.m_FormatString);
			else if (e.Value is int && e.DesiredType == typeof(string))
				e.Value = ((int)e.Value).ToString(this.m_FormatString);
		}
		protected override void ParseHandler(object sender, ConvertEventArgs e)
		{
			if (((string)e.Value).Trim().Length == 0)
				e.Value = "0";

			if (e.DesiredType == typeof(decimal))
				e.Value = Decimal.Parse((string)e.Value, System.Globalization.NumberStyles.Any);
			else if (e.DesiredType == typeof(int))
			{
				string[] s = ((string)e.Value).Trim().Split('.');
				e.Value = Decimal.Parse(s[0], System.Globalization.NumberStyles.Any);
			}
		}
		protected override void KeyPressHandler(object sender, KeyPressEventArgs e)
		{
			// Prevent illegal characters
			bool allowed = false;
			for (int i = 0; i < this.AllowedChars.Length; i++) 
			{
				if (e.KeyChar == this.AllowedChars[i])
				{
					allowed = true;
					break;
				}
			}

			if (allowed == true)
			{
				string CurrentText = this.Text;
				if (this.SelectionLength > 0)
				{
					int i = this.Text.IndexOf(this.SelectedText);
					int j = i + this.SelectionLength;

					if (i > 0 && j == this.TextLength)
						CurrentText = this.Text.Substring(0, i);
					else
					if (i > 0)
						CurrentText = this.Text.Substring(0, i) + this.Text.Substring(j);
					else
						CurrentText = this.Text.Substring(j);
				}
				if (CurrentText != this.SelectedText)
				{
					// Prevent duplicates of decimal point and minus sign
					if ((e.KeyChar == '.' || e.KeyChar == '-') && 
						CurrentText.IndexOf(e.KeyChar) >= 0)
						e.Handled = true;
					else
					{
						// Prevent too many digits on either side of decimal point
						if (this.m_DecimalPlaces > 0 && 
							e.KeyChar != '.' && e.KeyChar != '-' && e.KeyChar != (char)Keys.Back)
						{
							int MaxDecimalPos = this.MaxLength - this.m_DecimalPlaces - 1;
							int DecimalPos    = CurrentText.IndexOf('.');
							int DecimalDigits = CurrentText.Length - DecimalPos - 1;

							if (DecimalPos < 0)
							{
								if (CurrentText.Length >= MaxDecimalPos)
									e.Handled = true;
							}
							else
							if (this.SelectionStart <= DecimalPos)
							{
								if (DecimalPos == MaxDecimalPos)
									e.Handled = true;
							}
							else
							if (this.SelectionStart >= CurrentText.Length)
							{
								if (DecimalDigits == this.m_DecimalPlaces)
									e.Handled = true;
							}

//							if (DecimalPos > MaxDecimalPos)
//								e.Handled = true;
//							else
//							if (CurrentText.Length > DecimalPos + this.m_DecimalPlaces)
//								e.Handled = true;
						}
					}
				}
			}
			else
				e.Handled = true;
		}

		protected override void ValidatingHandler(object sender, CancelEventArgs e)
		{
			if (this.Text.Trim().Length == 0)
				return;

			try
			{
				decimal test = Decimal.Parse(this.Text);
				if (test > this.m_Maximum || test < this.m_Minimum)
				{
					string message = "The value for this field must be between " +
						this.m_Maximum.ToString() + " and " + this.m_Minimum.ToString() + "!";
					string caption = "Value out of range";
					MessageBox.Show(message, caption, MessageBoxButtons.OK, MessageBoxIcon.Error);

					e.Cancel = true;
				}
			}
			catch (Exception ex)
			{
				System.Diagnostics.Debug.WriteLine(ex.Message);
			}
		}
		#endregion

		#region Properties
		[Description("The number of digits to display after the decimal.")]
		[DefaultValue(0)]
		public int DecimalPlaces
		{
			get {return this.m_DecimalPlaces;}
			set
			{
				this.m_DecimalPlaces = value;

				// Create the AllowedChars array for the KeyPress event handler
				if (value > 0 && this.m_Minimum < 0)
					this.AllowedChars = new char[] {(char)Keys.Back, '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', 

'.', '-'};
				else if (value > 0)
					this.AllowedChars = new char[] {(char)Keys.Back, '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', 

'.'};
				else if (this.m_Minimum < 0)
					this.AllowedChars = new char[] {(char)Keys.Back, '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', 

'-'};
				else
					this.AllowedChars = new char[] {(char)Keys.Back, '1', '2', '3', '4', '5', '6', '7', '8', '9', '0'};

				// Create the FormatString property value
				string[] format = this.m_FormatString.Split(new char[] {'.'}, 2);
				if (value > 0)
				{
					string s = new string('0', value);
					this.m_FormatString = format[0] + "." + s;
				}
				else
					this.m_FormatString = format[0];

				this.MaxLength = this.m_FormatString.Length;
				if (this.m_Minimum < 0 && this.m_Minimum.ToString().Length > this.m_Maximum.ToString().Length)
					this.MaxLength++;
			}
		}
		[Description("The maximum value allowed in the field.")]
		[DefaultValue(100)]
		public decimal Maximum
		{
			get {return this.m_Maximum;}
			set
			{
				if (value < this.m_Minimum)
					return;

				this.m_Maximum = value;

				// Create the first half of the FormatString property
				this.MaxLength = value.ToString().Length;
				int max = this.m_Minimum.ToString().Length;
				if (this.m_Minimum < 0 && max > this.MaxLength)
					this.MaxLength = max;

				if (this.MaxLength > 2 && value.ToString().Length < this.m_Minimum.ToString().Length)
					this.m_FormatString = new string('#', this.MaxLength - 2) + "0";
				else if (this.MaxLength > 1)
					this.m_FormatString = new string('#', this.MaxLength - 1) + "0";
				else
					this.m_FormatString = "0";

//				if (this.m_Minimum < 0)
//					this.m_FormatString = "-" + this.m_FormatString;

				// Finally, create the formatting
				this.DecimalPlaces = this.m_DecimalPlaces;
			}
		}
		[Description("The minimum value allowed in the field.")]
		[DefaultValue(0)]
		public decimal Minimum
		{
			get {return this.m_Minimum;}
			set
			{
				if (value > this.m_Maximum)
					return;
				
				this.m_Minimum = value;
				this.Maximum = this.m_Maximum;
			}
		}

		[Description("Enable if you don't want to display a zero in this field")]
		public bool DisplayDefaultZero
		{
			get {return this.m_DisplayDefaultZero;}
			set {this.m_DisplayDefaultZero = value;}
		}
//		[Description("The string to use with ToString to format.")]
//		[DefaultValue("##0")]
//		public string FormatString
//		{
//			get {return this.m_FormatString;}
//			set {this.m_FormatString = value;}
//		}
		#endregion
	}

~~Bonnie