ASP coding problems

Use server. URLEncode (str) to write str code to the database.
The following are decoding functions:
<%
Function DeCode (EnStr)
For I = 1 To Len (EnStr)
C = Mid (EnStr, I, 1)
If C = "%" Then
V = Eval ("& H" & Mid (EnStr, I + 1, 2 ))
If V <128 Then
DeCode = DeCode & Chr (V)
I = I + 2
Else
If Isvalidhex (Mid (EnStr, I, 3) Then
If Isvalidhex (Mid (EnStr, I + 3, 3) Then
V = Eval ("& H" & Mid (EnStr, I + 1, 2) & Mid (EnStr, I + 4, 2 ))
DeCode = DeCode & Chr (V)
I = I + 5
Else
V = Eval ("& H" & Mid (EnStr, I +) & Cstr (Hex (Asc (Mid (EnStr, I + )))))
DeCode = DeCode & Chr (V)
I = I + 3
End If
Else
DeCode = DeCode & C
End If
End If
Else
If C = "+" Then
DeCode = DeCode &""
Else
DeCode = DeCode & C
End If
End If
Next
End Function
Function Isvalidhex (Str)
Isvalidhex = True
Str = Ucase (Str)
If Len (Str) <> 3 Then Isvalidhex = False: Exit Function
If Left (Str, 1) <> "%" Then Isvalidhex = False: Exit Function
C = Mid (Str, 2, 1)
If Not (C> = "0") And (C <= "9") Or (C> = "") and (C <= "Z") Then Isvalidhex = False: Exit Function
C = Mid (Str, 3,1)
If Not (C> = "0") And (C <= "9") Or (C> = "") and (C <= "Z") Then Isvalidhex = False: Exit Function
End Function
%>