Check to see if input box content is uppercase

hmm... try this out (see attached to run the macro and step through to see what's it's doing:

Needed a little more code to do this...found a way to loop and repeat the query until the input is OK

Enjoy and rate please

Option Explicit

Sub testcontrol()

Dim TestInput As String
Dim isOK As Boolean
Dim i As Integer, passes As Integer

isOK = False
passes = 0
Do

If passes > 0 Then
'prompt again
    MsgBox ("please only enter upper-case letters and number at next prompt")
    TestInput = InputBox("UpperCase Letters & Number only please")
Else
    TestInput = InputBox("UpperCase Letters & Number only please")
End If

passes = passes + 1
For i = 1 To Len(TestInput)
    isOK = checkValidity(Mid(TestInput, i, 1))
    If isOK = False Then
    'bounce
        i = Len(TestInput)
    End If
Next i
Loop While Not isOK
End Sub

Function checkValidity(test As String) As Boolean
Dim i As Integer
Dim ok As Boolean
Dim valarray(1 To 36) As String

ok = False
valarray(1) = "A"
valarray(2) = "B"
valarray(3) = "C"
valarray(4) = "D"
valarray(5) = "E"
valarray(6) = "F"
valarray(7) = "G"
valarray(8) = "H"
valarray(9) = "I"
valarray(10) = "J"
valarray(11) = "K"
valarray(12) = "L"
valarray(13) = "M"
valarray(14) = "N"
valarray(15) = "O"
valarray(16) = "P"
valarray(17) = "S"
valarray(18) = "T"
valarray(19) = "W"
valarray(20) = "X"
valarray(21) = "Y"
valarray(22) = "Z"
valarray(23) = "0"
valarray(24) = "1"
valarray(25) = "2"
valarray(26) = "3"
valarray(27) = "4"
valarray(28) = "5"
valarray(29) = "6"
valarray(30) = "7"
valarray(31) = "8"
valarray(32) = "9"

For i = 1 To 36
    If test = valarray(i) Then
        ok = True
    End If
Next i

checkValidity = ok

End Function