How to check if text box max length has been exceeded?

'How to check if text box max length has been exceeded?
'http://stackoverflow.com/questions/26534314/how-to-check-if-text-box-max-length-has-been-exceeded
'Corrected logic (full code using tooltips).

Public Class Form1
    Private Sub Textbox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        If Not IsNumeric(TextBox1.Text) Then
            If TextBox1.Text.Length > 8 Then
                TextBox1.Text = TextBox1.Text.Substring(0, 8)
                TextBox1.Select(TextBox1.TextLength, 0)
                ToolTip1.IsBalloon = True
                ToolTip1.ToolTipTitle = "8 character maximum and input must be numeric!"
                ToolTip1.Active = True
                ToolTip1.ToolTipIcon = ToolTipIcon.Warning
                ToolTip1.Show(vbNewLine, TextBox1, 45, -40, 2000)
            ElseIf TextBox1.Text.Length > 0 Then
                If ToolTip1.GetToolTip(TextBox1) = "" Then
                    ToolTip1.ToolTipTitle = "Input must be numeric!"
                    ToolTip1.Active = True
                    ToolTip1.IsBalloon = True
                    ToolTip1.ToolTipIcon = ToolTipIcon.Warning
                    ToolTip1.Show(vbNewLine, TextBox1, 45, -40, 2000)
                End If
            End If
        Else
            If TextBox1.Text.Length > 8 Then
                TextBox1.Text = TextBox1.Text.Substring(0, 8)
                TextBox1.Select(TextBox1.TextLength, 0)
                ToolTip1.IsBalloon = True
                ToolTip1.ToolTipTitle = "8 character maximum!"
                ToolTip1.Active = True
                ToolTip1.ToolTipIcon = ToolTipIcon.Warning
                ToolTip1.Show(vbNewLine, TextBox1, 45, -40, 2000)
            Else
                ToolTip1.Active = False
                ToolTip1.Hide(TextBox1)
            End If
        End If
    End Sub
End Class