ASP file download code

<%
Dim Url,strurl,strpath
Dim Strinceptfile
Strinceptfile = "SWF,FLA,JPG,JPEG,GIF,PNG,BMP,TIF,IFF,MP3,WMA,RM,WMV,MID,RMI,CDA,AVI,MPG,MPEG,RA,RAM,WOV,ASF"
url = replace (replace (Request ("url"), "'", ""), "%", "" "," "," "/"

If Len (URL) > 3 Then
If Left (url,1) = "/" Then
Response.Redirect URL
End If
If InStr (URL, "..."). /") > 0 Then
Response.Redirect URL
End If
strURL = Left (url,10)
If InStr (strURL, "://") > 0 Then
Response.Redirect URL
End If
If InStr (URL, "/") > 0 Then
URL =replace (URL, "..."). /", "")
If checkfileext (URL) Then
strpath = Server.MapPath (".") & "" & URL
strpath = Replace (strpath, "/", "")
Call Downthisfile (strpath)
End If
Else
Response.Redirect URL
End If
End If

Sub Downthisfile (Thepath)
Response.Clear
On Error Resume Next
Dim Stream, FileName, Filecontenttype

FileName = Split (Thepath, "") (UBound (Split (Thepath, ""))
Set stream = Server.CreateObject ("ADODB.stream")
Stream. Open
Stream. Type = 1
Stream. LoadFromFile (Thepath)
Response.AddHeader "Content-disposition", "attachment"; Filename= "& FileName
Response.AddHeader "Content-length", stream. Size
Response.Charset = "UTF-8"
Response.ContentType = "Application/octet-stream"
Response.BinaryWrite Stream. Read
Response.Flush
Stream. Close
Set stream = Nothing
End Sub

Function Checkfileext (ByVal strfile)
Dim Arrinceptfile
Dim I, Strfileext

On Error Resume Next

If Trim (strfile) = "" Or isempty (strfile) Then
Checkfileext = False
Exit Function
End If

Strfileext = Getfileextname (strfile)
Strfileext = LCase (Strfileext)
Strinceptfile = LCase (strinceptfile)
If Len (Strinceptfile) = 0 Then
Checkfileext = True
Exit Function
End If
Arrinceptfile = Split (Strinceptfile, ",")

For i = 0 to UBound (arrinceptfile)
If trim (strfileext) = Trim (Arrinceptfile (i)) Then
Checkfileext = True
Exit Function
Else
Checkfileext = False
End If
Next
Checkfileext = False
End Function
Function getfileextname (ByVal strFilePath)
Dim Strextname
Strextname = Mid (strFilePath, InStrRev (strFilePath, ".") + 1)
If InStr (Strextname, "?") > 0 Then
Getfileextname = Left (Strextname, InStr (Strextname, "?")-1)
Else
Getfileextname = Strextname
End If
End Function
%>