ACC2000: Flexible Input Mask for Entering Five- or Nine-Digit ZIP Codes (208949)

MORE INFORMATION

• Convert the ZIP code into a text string.
• Strip the text string of any parentheses, spaces, or dashes.
• Determine whether the ZIP code contains any alphabetical characters, and if so, terminate the function and alert the user.

1. Create a new module and enter the following line in the Declarations section if it is not already there:

   Option Explicit
   					

2. Enter the following code in the module:

   Function Zip (zipcode As Control)
   
     'Exit if a null is passed to the function.
     If IsNull(zipcode) Then
       Exit Function
     End If
     If IsThereAlpha(zipcode) Then
       Msgbox "Your ZIP Code Contains Letters"
       Exit Function
     Else
       'Strip unwanted characters, leaving only numbers.
       zipcode = ZStrip(zipcode, "-")
       zipcode = ZStrip(zipcode, " ")
       zipcode = ZStrip(zipcode, ")")
       zipcode = ZStrip(zipcode, "(")
   
       'Reformat the character string.
       Select Case Len(zipcode)
         Case 5
           Screen.ActiveControl = Format(zipcode, "@@@@@")
         Case 9
           Screen.ActiveControl = Format(zipcode, "@@@@@-@@@@")
         Case Else
           MsgBox "This is not a valid ZIP Code."
           Screen.ActiveControl = zipcode
       End Select
     End If
   End Function
   
   Function ZStrip (InZip, StripZip)
     Do While InStr(InZip, StripZip)
       InZip = Mid(InZip, 1, InStr(InZip, StripZip) - 1) & Mid _
       (InZip, InStr(InZip, StripZip) + 1)
     Loop
     ZStrip = InZip
   End Function
   
   Function IsThereAlpha (zipcode) As Integer
      Dim Pos, a_char$, Clean
      Pos = 1
      Clean = 0
      While (Pos <= Len(zipcode) And (Clean = 0))
         a_char$ = Mid(zipcode, Pos, 1)
         If a_char$ >= "0" And a_char$ <= "9" Then
            Clean = 0
         Else
            If a_char$ <> "-" Then Clean = 1
         End If
         Pos = Pos + 1
      Wend
      IsThereAlpha = Clean
   End Function
   
   					

3. Type the following in the ValidationRule property of the control that contains the ZIP code:
   
   Len([Control name]) = 5 or Len([Control name]) = 9
4. Type the following for the validation text for the control:
   
   This is not a valid ZIP code. ZIP codes must be 5 or 9 characters in length. Please re-enter the correct ZIP code.
5. Set the AfterUpdate property of the control on your form that contains the ZIP codes to the expression =Zip([<controlname>]) where <controlname> is the name of the control that contains the ZIP codes.