VB.NET / SQL CLR / Decode encoded URL

Immersing myself in VB for SQL CLR functionality I found this to Decode an encoded URL.

I've made one minor change from chr$ to chr to make it complient for .NET 3.5

Private Shared Function URLDecode(ByVal txt As String) As String
Dim txt_len As Integer
Dim i As Integer
Dim ch As String
Dim digits As String
Dim result As String

result = ""
txt_len = Len(txt)
i = 1
Do While i <= txt_len
' Examine the next character.
ch = Mid$(txt, i, 1)
If ch = "+" Then
' Convert to space character.
result = result & " "
ElseIf ch <> "%" Then
' Normal character.
result = result & ch
ElseIf i > txt_len - 2 Then
' No room for two following digits.
result = result & ch
Else
' Get the next two hex digits.
digits = Mid$(txt, i + 1, 2)
result = result & Chr(CInt("&H" & digits))
i = i + 2
End If
i = i + 1
Loop

URLDecode = result
End Function