' Enable the key-skipping mechanism for the input TextBox and for the input ' chars' Example: don't process the 'A', 'b' and '0' chars'   EnableTextBoxCharSkip(TextBox1, "A"c, "b"c, "0"c)Sub EnableTextBoxCharSkip(ByVal tb As TextBox, ByVal ParamArray keysToSkip() As _    Char)    ' save the array of keys textbox's Tag property    tb.Tag = keysToSkip    ' attach the txtbox's KeyPress event to the GenTextBox_KeyPress event     ' handler    AddHandler tb.KeyPress, AddressOf GenTextBox_KeyPressEnd Sub' Disable the key-skipping mechanism for the input textbox' Example: DisableTextBoxCharSkip(TextBox1)Sub DisableTextBoxCharSkip(ByVal tb As TextBox)    ' detach the textbox's KeyPress event from the GenTextBox_KeyPress event     ' handler    RemoveHandler tb.KeyPress, AddressOf GenTextBox_KeyPress    tb.Tag = NothingEnd Sub' Handle the textbox's KeyPress event to skip the keys of the array stored in ' the textbox's Tag propertyPrivate Sub GenTextBox_KeyPress(ByVal sender As Object, _    ByVal e As System.Windows.Forms.KeyPressEventArgs)    ' cast the generic Object sender to a TextBox    Dim tb As TextBox = DirectCast(sender, TextBox)    ' cast the textbox's Tag to an array of Char, that contains the chars to     ' skip    Dim keysToSkip() As Char = DirectCast(tb.Tag, Char())    ' if the pressed key is found in the array of "bad" keys,    '  overrides its default processing with "do nothing"    If Array.IndexOf(keysToSkip, e.KeyChar) > -1 Then e.Handled = TrueEnd Sub