It's Very Easy to make a Numeric only TextBox ..

Just right the Following Code on The Textbox's KeyPress Event..

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)        {            if (e.KeyChar > 31 && (e.KeyChar < '0' || e.KeyChar > '9'))            {                e.Handled = true;            }        }

Above Code Wont Let you enter anything other than 0 to 9 Numerics

To Limit the Number of Character in Texbox use the MaxLength Property  of Texbox

Example:

TextBox1.MaxLength = 10;

Vb.net

Private Sub TextBox1_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress        If e.KeyChar > "31" And (e.KeyChar < "0" Or e.KeyChar > "9") Then            e.Handled = True        End If    End Sub

Example:

TextBox1.MaxLength = 10