Using If .. Then to skip a blank combo box in a For...Next

The problem is that I need to check combo boxes against each other. I did most of the work, but I don't know what to do about blank boxes. Code is below.

Dim j As Long
For j = 1 To 15
    If Me.Controls("cmbVol" & j).Value = BLANK Then
        
    Else
        If j > 1 Then
            Dim q As Long
            For q = 1 To (j - 1)
                If Me.Controls("cmbVol" & j).Value = Me.Controls("cmbVol" & q).Value Then
                    MsgBox "Yep you did it again"
                    Exit Sub
                End If
            Next q
            
            Dim w As Long
            For w = (j + 1) To 15
                If Me.Controls("cmbVol" & j).Value = Me.Controls("cmbVol" & w).Value Then
                    MsgBox "Yep you did it this time"
                    Exit Sub
                End If
            Next w
        Else
            Dim e As Long
            For e = 2 To 15
                If Me.Controls("cmbVol" & j).Value = Me.Controls("cmbVol" & e).Value Then
                    MsgBox "Ok Still it"
                    Exit Sub
                End If
            Next e
    End If
Next j

In the first "If" I need something for it to do in order to skip and go on to Next j...such as a Null. But you can't just write null there.

Or I can reverse the code and use the first if as Not Blank, but I also don't know how to do that.

Any help is appreciated.


Extra info:
Combo boxes are named "cmbVol1" - "cmbVol15"
They cannot be equal to each other but will not always be filled in. Most of the time there will be some blank ones.
The goal is to make sure that anything that does have info in it is not the same as something in another box and if so msgBox with message that says so.

I didn't look too closely at this, but if you're just trying to skip one, you could try this--although it really should be doing that on it's own with the If/Else statement

Dim j As Long
For j = 1 To 15
    If Me.Controls("cmbVol" & j).Value = BLANK Then
        GoTo SkipMe
    Else
        If j > 1 Then
            Dim q As Long
            For q = 1 To (j - 1)
                If Me.Controls("cmbVol" & j).Value = Me.Controls("cmbVol" & q).Value Then
                    MsgBox "Yep you did it again"
                    Exit Sub
                End If
            Next q
            
            Dim w As Long
            For w = (j + 1) To 15
                If Me.Controls("cmbVol" & j).Value = Me.Controls("cmbVol" & w).Value Then
                    MsgBox "Yep you did it this time"
                    Exit Sub
                End If
            Next w
        Else
            Dim e As Long
            For e = 2 To 15
                If Me.Controls("cmbVol" & j).Value = Me.Controls("cmbVol" & e).Value Then
                    MsgBox "Ok Still it"
                    Exit Sub
                End If
            Next e
    End If
SkipMe: Next j

Could also try this:

    Dim ctControl As Control
    Dim ctControl2 As Control
    
    For Each ctControl In Me.Controls
        If Left(ctControl.Name, Len("cmbVol")) = "cmbVol" Then
            For Each ctControl2 In Me.Controls
                If Left(ctControl2.Name, Len("cmbVol")) = "cmbVol" Then
                    If Len(ctControl.Text) > 0 And ctControl.Text = ctControl2.Text _
                        And Not ctControl Is ctControl2 Then
                        ctControl2.SetFocus
                        MsgBox "duplicate value...select something else"
                        Exit Sub
                    End If
                End If
            Next
        End If
    Next

Here it is with some comments. If anything doesn't make sense, feel free to ask. Thanks!

    Dim ctControl As Control
    Dim ctControl2 As Control
    
    'Loop through all controls on the form (Me is the form in this case)
    'the control will be assigned to ctControl
    For Each ctControl In Me.Controls
        'Only look at controls whose names begin with cmbVol
        If Left(ctControl.Name, Len("cmbVol")) = "cmbVol" Then
            'Loop through all controls again but this time the control is assigned
            'to ctControl2
            For Each ctControl2 In Me.Controls
                'Check again to see if the control name begins with cmbVol
                If Left(ctControl2.Name, Len("cmbVol")) = "cmbVol" Then
                    'If the control from the first loop is not empty (len(ctControl.text)>0)
                    'and the control form loop 1 has the same text as the control from loop 2
                    'and the control from loop 1 is not the same control from loop 2 then
                    'set the focus to the loop 2 control (ctControl2.SetFocus) and
                    'show a message box explaining the problem...then exit the sub
                    If Len(ctControl.Text) > 0 And ctControl.Text = ctControl2.Text _
                        And Not ctControl Is ctControl2 Then
                        ctControl2.SetFocus
                        MsgBox "duplicate value...select something else"
                        Exit Sub
                    End If
                End If
            Next
        End If
    Next