Need additional help w/ "For Each ctl In Me.Controls" function

A few days ago, shanesuebsahakarn helped me to come up w/ a great "validation function".

Here's what I have:
- Main form w/ tab control
- Tab control has 3 tabs
- Tab0 and Tab1 have required controls (both textfield and combos); Tab2 doesn't have any required controls at this time

Here's what the function does:
- If I do NOT complete all required controls on e.g. tab0 and click on tab1, all required controls on Tab0 are highlighted in yellow; moreover, the function sets focus to the "1st invalid" (no data) control vs. to the "1st control on page" (whether valid or invalid)
- the same process for tab1... if I completed everything on tab0 and then move to tab1 but forget to complete all required controls on tab1, I get the error message when clicking on tab2

Moreover, I cannot create a new record until all required controls have received a value.  That in itself is a HUGE PLUS!

Okay, here's the small problem:
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Strangely, the "timing of the error message" as well as the "sending back to tab w/ errors" does not always work consistently the same.   Let me provide some scenarios that describe the inconsistent behavior.  

I have run the record creation and the "error-making" over and over again... I couldn't say though and it always works "consistently incosistent".  Sometimes it works as expected... other times it doesn't.  

Okay, here's what I have noticed thus far:

Scenario 1:
- I create a new record
- purposely, I leave 1st required control empty but complete the rest on tab0
- click on tab1
- I get the error message and I'm sent back to tab0 and 1st required control has focus
- ... that's a perfect scenario

Scenario 2:
- I repeat scenario 1 (but now leave multiple required controls empty on tab0) ....
- at this time, I should have been sent back to tab0 but I'm not
- instead, I can go to tab1 and complete all required controls (or leave some blank)
- then I click on tab2
- now I'm being sent back to tab0
- ... again, record completion of scenario1 and scenario2 is identical, the error message activation is differnt

Scenario 3:
- I repeat scenario 1 a 3rd time....
- now I don't even get the error message when clicking on tab2.
- Instead I can leave all required fields empty and manquever freely from tab to tab... and I don't get any errror messages whatsover
- Luckily, however, the error message eventually kicks in when attempting to create another record


Now, maybe I'm trying to make this "too perfect"... however, I'm wondering if there is something minor that can be done that ensures consistent error handling, which is:
- I forget some required control on a tab and I cannot select another tab until I fixed the control on the current tab


++++++++++++++++++++++++++

So, my questions are:

1. Does anyone know of an easy solution?

2. Also -- and this goes beyond everything listed previously -- how can I include required fields in a subform as well?

++++++++++++++++++++++++++


Thanks,
Tom





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Option Compare Database
Option Explicit
Dim lngTabPage As Long

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Private Sub Form_BeforeUpdate(Cancel As Integer)
   
    Dim ctl As Control
    Dim NotComplete As Boolean
    Dim strControlName As String
    'The global variable "lngTabPage" is declared at the top of the module
    'lngTabPage keeps track of the required controls per tab (tabs 0,1,2 have values: R0, R1, R2)

    'Keeps track of the "next invalid" control (unselected/no data)
    strControlName = ""
   
    NotComplete = False
    For Each ctl In Me.Controls
       If ctl.Tag = "R" & lngTabPage Then
          If (ctl.Value & "") = "" Then
             ctl.BackColor = vbYellow
             NotComplete = True
             If strControlName = "" Then strControlName = ctl.Name
           End If
        End If
    Next
   
    If NotComplete Then
       Cancel = True
       Me!RRISTabControl = lngTabPage
       Me(strControlName).SetFocus
       MsgBox "You must complete the yellow highlighted field!", vbCritical, "Required Data Missing"
    Else
       lngTabPage = Me!RRISTabControl
    End If
End Sub  
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