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

• Microsoft Access 2000

SUMMARY

This article shows you how to create a flexible input mask for entering either 5- or 9-digit ZIP codes in a field on a form.

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MORE INFORMATION

The method demonstrated in this article uses three user-defined sample Visual Basic for Applications functions that do the following:

• 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.

REFERENCES

For more information about input masks, click Microsoft Access Help on the Help menu, type input masks in the Office Assistant or the Answer Wizard, and then click Search to view the topics returned.

Additional query words:

Keywords : kbdta AccCon FmsProp KbVBA
Version : WINDOWS:2000
Platform : WINDOWS
Issue type : kbinfo