What about TRIM() ?

What about TRIM() for removing white space from strings!
Although it is a really handy BUG-ELIMINATOR for whenever a user pastes into your (MS-Access) application, STILL this attachment demonstrates that TRIM only works on outer spaces, not other white space characters like ASCII characters 9, 10, 12, 13. (vbTab, vbLf, Formfeed, vbCr)

' Save  this in a VBS file on your desktop for a VISUAL DEMO comparing three string cleaning functions below
Dim someOtherString, someOtherString1, someOtherString2, someOtherString3

someOtherString1 = vbCrLf & vbTab & "Hi Mom!" & int(rnd(100)*5) & vbTab & vbCrLf
someOtherString2 = vbCrLf & vbTab & "Hi Mom!" & int(rnd(100)*5) & vbTab & vbCrLf
someOtherString3 = vbCrLf & vbTab & "Hi Mom!" & int(rnd(100)*5) & vbTab & vbCrLf

msgbox chr(34) & trim(someOtherString1) & chr(34),,"Trim"
msgbox chr(34) & nibble(someOtherString2) & chr(34),,"Nibble"
msgbox chr(34) & chomp(someOtherString3) & chr(34),,"Chomp"
' --------------------
Function chomp(somestring)
if len(somestring) >= 1 then 
while (asc(right(somestring,1)) <= 13 ) 
   somestring = left(somestring, len(somestring)-1) 
end if 
chomp = somestring  
End Function 

' -------------------- 

Function nibble(somestring) 
 if len(somestring) >= 1 then 
   while (asc(left(somestring,1)) <= 13 ) 
somestring = right(somestring, len(somestring)-1) 
end if 
nibble = somestring  
End Function

See http://excel-on-demand.com/2017/01/25/vbcommon-chomp-nibble/

Excel Macro Autonumber NonBlanks

Sub NumbernonBlankTestLines()
' user must manually highlight range in Column A
Dim msgs, qy, rep
Dim testcount, r, c As Integer,
Dim startHere As Range, rngSelected As Range
Dim markblank, enforcesinglerowblank As Boolean
enforcesinglerowblank = False

' MsgBox "last cell is " & findlastusedcell()
' use if we add feature to insert column A and auto-select range

testcount = 0

Set startHere = ActiveCell
Set rngSelected = Selection

If TypeName(Selection) = "Range" Then
If Selection.Areas.Count = 1 Then
' MsgBox "selected rows is " & rngSelected.Rows.Count & vbCrLf & "columnn is " & ActiveCell.Column

If rngSelected.Rows.Count < 2 Or ActiveCell.Column <> 1 Then GoTo oops

' magic starts here
'Selection.Name = "eraseme"
markblank = False
'MsgBox rngSelected.Rows.Count

If WorksheetFunction.CountA(rngSelected) > 1 Then
qy = MsgBox("OVERWRITE existing DATA?", vbOKCancel, "WARNING!")
If qy = vbCancel Then
Exit Sub
End If
End If
For r = 1 To rngSelected.Rows.Count


If r = 1 Then
If rngSelected(r).Offset(0, 1) = "" Then
MsgBox rngSelected(r).Offset(0, 1).Value
GoTo oops
End If
End If

'case not blank
If rngSelected(r).Offset(0, 1) > "" Then
If enforcesinglerowblank And markblank Then
GoTo doublelineerror
ElseIf Not markblank Or Not enforcesinglerowblank Then
markblank = Not markblank
rngSelected(r).Value = testcount + 1
' markblank = False Else markblank = True
testcount = testcount + 1
End If
'case blank
ElseIf rngSelected(r).Offset(0, 1) = "" Then
If enforcesinglerowblank And Not markblank Then
GoTo doublelineerror
ElseIf markblank Then
markblank = Not markblank
End If
Else: MsgBox
"Unknown", vbCritical, "Error!"

End If

Next r
' GoTo A1
MsgBox "Numbered " & testcount & " rows"
'measure column B begin and end
'make temporary range from A2: to match B begin to B end

'tbd select column A
'if selection < 2 rows warn and exit
'for each row in A, test adjacent cell B has value - number A, set flag notblank
'if flag notblank then next row should be blank, else warn andexit else skip to next
'if flag notblank, then next row should NOT be blank, else warn and exit, else number A
"Please select only one area.", vbInformation
End If
End If
Exit Sub

MsgBox "Only one row per test, MUST be separated by exactly one blank row: see Test# " & testcount, vbCritical, "Halted / Config Error"

Exit Sub

MsgBox "HALTED: must select multiple continuous rows within column A, alongside alternating data in column B" & vbCrLf _
& "and first selected row is NOT blank", vbCritical, "SELECTION ERROR"

End Sub