Forms: Make Numeric and Date fields respond to Plus or Minus keys

Often times it's necessary to have the Plus/Minus keys act as spin controls in a numeric or text fields, in other words, have the date/number increase/decrease it's value when the plus or the minus keys are pressed.

You can use this public function from the KeyPress event of a control to have the desired effect on the value of the control.

'**************** Code Start **************
' This code was originally written by Jason Looney.
' It is not to be altered or distributed,
' except as part of an application.
' You are free to use it in any application,
' provided the copyright notice is left unchanged.
'
' Code Courtesy of
' Jason Looney
'
Public Function PlusMinus(intKey As Integer, strFormName As String, Optional _
    strSubformName As String = "", Optional strSubSubFormName As String = "") _
    As Integer

'Allows a date or number field on a form or subform to respond to plus/minus keys
'Sample Usages (in the Keypress event):
'   Call PlusMinus(KeyAscii, Me.Name)
'   Call PlusMinus(KeyAscii, Me.Parent.Name, Me.Name)
'   Call PlusMinus(KeyAscii, Me.Parent.Parent.Name, Me.Parent.Name, Me.Name)

On Error GoTo TheHandler
Dim ctl As Control
    
    If strSubformName <> "" Then
        If strSubSubFormName <> "" Then
            Set ctl = Forms(strFormName).Controls(strSubformName).Form.Controls(strSubSubFormName).Form.ActiveControl
        Else
            Set ctl = Forms(strFormName).Controls(strSubformName).Form.ActiveControl
        End If
    Else
        Set ctl = Forms(strFormName).ActiveControl
    End If
    
    ctl = CDate(ctl)
    
    Select Case intKey
        Case Is = 43        'the '+' key
            ctl = ctl + 1
            intKey = 0
        Case Is = 45        'the '-' keys
            ctl = ctl - 1
            intKey = 0
        Case Is = 61        'the '='/'+' key next to Backspace
            ctl = ctl + 1
            intKey = 0
    End Select
           
ExitHandler:
    PlusMinus = intKey
    Set ctl = Nothing
    Exit Function

TheHandler:
    Select Case Err.Number
        Case Is = 94    'Invalid use of null
        Case Is = 13    'Type mismatch
        Case Else
            MsgBox Err.Number & ":  " & Err.Description
            intKey = 0
    End Select
    Resume ExitHandler
End Function
'**************** Code End  **************