NullSpace

Function IsNullString(Text As String) As Boolean
Dim i As Long
For i = 1 To Len(Text)
Select Case Asc(Mid$(Text, i, 1))
Case 0, 9, 32
Case Else
Exit Function
End Select
Next
IsNullString = True
End Function

Return True is a string is made only of spaces, tabs, and Null
characters.
This function is especially useful to test whether fixed-length
strings are initialized.