The information in this article applies to:
- Microsoft Access versions 1.0, 1.1, 2.0, 7.0, 97
SUMMARY
This article describes a method of creating a flexible input mask for
entering either 5- or 9-digit ZIP codes in a field on a form.
This article assumes that you are familiar with Visual Basic for
Applications and with creating Microsoft Access applications using the
programming tools provided with Microsoft Access. For more information
about Visual Basic for Applications, please refer to your version of the
"Building Applications with Microsoft Access" manual.
NOTE: Visual Basic for Applications is called Access Basic in Microsoft
Access versions 1.x and 2.0. For more information about Access Basic,
please refer to the "Introduction to Programming" manual in Microsoft
Access version 1.x or the "Building Applications" manual in Microsoft
Access version 2.0.
MORE INFORMATION
The method demonstrated in this article uses three user-defined sample
Visual Basic (or Access Basic) functions that perform the following tasks:
- 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.
To set up the input mask, follow these steps:
- Create a new module and enter the following line in the Declarations
section if it is not already there:
Option Explicit
- Enter the following code in the module.
NOTE: In the following sample code, an underscore (_) at the end of a
line is used as a line-continuation character. Remove the underscore
from the end of the line when re-creating this code in Access Basic.
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
- Type the following in the ValidationRule property of the control that
contains the zip code:
Len([Control name]) = 5 or Len([Control name]) = 9
- 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.
- 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 using input masks, search the Help Index for
"input masks," and then "Create an input mask to control how data is
entered in a field or control."
Keywords : FmsProp kbusage
Version : 1.0 1.1 2.0 7.0 97
Platform : WINDOWS
Hardware : x86
Issue type : kbinfo
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