how do you use ASP Upload?

Here I have some source code that you can change it for your own perpose:

<%
Response.Buffer = true
Function BuildUpload(RequestBin)
     'Get the boundary
     PosBeg = 1
     PosEnd = InstrB(PosBeg,RequestBin,getByteString(chr(13)))
     boundary = MidB(RequestBin,PosBeg,PosEnd-PosBeg)
     boundaryPos = InstrB(1,RequestBin,boundary)
     'Get all data inside the boundaries
     Do until (boundaryPos=InstrB(RequestBin,boundary & getByteString("--")))
          'Members variable of objects are put in a dictionary object
          Dim UploadControl
          Set UploadControl = CreateObject("Scripting.Dictionary")
          'Get an object name
          Pos = InstrB(BoundaryPos,RequestBin,getByteString("Content-Disposition"))
          Pos = InstrB(Pos,RequestBin,getByteString("name="))
          PosBeg = Pos+6
          PosEnd = InstrB(PosBeg,RequestBin,getByteString(chr(34)))
          Name = getString(MidB(RequestBin,PosBeg,PosEnd-PosBeg))
          PosFile = InstrB(BoundaryPos,RequestBin,getByteString("filename="))
          PosBound = InstrB(PosEnd,RequestBin,boundary)
          'Test if object is of file type
          If PosFile<>0 AND (PosFile<PosBound) Then
               'Get Filename, content-type and content of file
               PosBeg = PosFile + 10
               PosEnd = InstrB(PosBeg,RequestBin,getByteString(chr(34)))
               FileName = getString(MidB(RequestBin,PosBeg,PosEnd-PosBeg))
               'Add filename to dictionary object
               UploadControl.Add "FileName", FileName
               Pos = InstrB(PosEnd,RequestBin,getByteString("Content-Type:"))
               PosBeg = Pos+14
               PosEnd = InstrB(PosBeg,RequestBin,getByteString(chr(13)))
               'Add content-type to dictionary object
               ContentType = getString(MidB(RequestBin,PosBeg,PosEnd-PosBeg))
               UploadControl.Add "ContentType",ContentType
               'Get content of object
               PosBeg = PosEnd+4
               PosEnd = InstrB(PosBeg,RequestBin,boundary)-2
               Value = MidB(RequestBin,PosBeg,PosEnd-PosBeg)
               Else
               'Get content of object
               Pos = InstrB(Pos,RequestBin,getByteString(chr(13)))
               PosBeg = Pos+4
               PosEnd = InstrB(PosBeg,RequestBin,boundary)-2
               Value = getString(MidB(RequestBin,PosBeg,PosEnd-PosBeg))
          End If
          UploadControl.Add "Value" , Value    
          UploadRequest.Add name, UploadControl    
          BoundaryPos=InstrB(BoundaryPos+LenB(boundary),RequestBin,boundary)
     Loop
End Function

Function getByteString(StringStr)
     For i = 1 to Len(StringStr)
          char = Mid(StringStr,i,1)
          getByteString = getByteString & chrB(AscB(char))
     Next
End Function

Function getString(StringBin)
     getString =""
     For intCount = 1 to LenB(StringBin)
          getString = getString & chr(AscB(MidB(StringBin,intCount,1)))
     Next
End Function

If request("Action")="1" then
     Response.Clear
     byteCount = Request.TotalBytes
    
     RequestBin = Request.BinaryRead(byteCount)
    
     Set UploadRequest = CreateObject("Scripting.Dictionary")

     BuildUpload(RequestBin)
    
     If UploadRequest.Item("blob").Item("Value") <> "" Then

          contentType = UploadRequest.Item("blob").Item("ContentType")
          filepathname = UploadRequest.Item("blob").Item("FileName")
          filename = Right(filepathname,Len(filepathname)-InstrRev(filepathname,"\"))
          FolderName = UploadRequest.Item("where").Item("Value")
          Path = Mid(Request.ServerVariables("PATH_TRANSLATED"), 1, Len(Request.ServerVariables("PATH_TRANSLATED")) - Len(Request.ServerVariables("PATH_INFO"))) & "\"
          ToFolder = Path & "\" & FolderName
          value = UploadRequest.Item("blob").Item("Value")
          filename = ToFolder & "\" & filename
          Set MyFileObject = Server.CreateObject("Scripting.FileSystemObject")
          Set objFile = MyFileObject.CreateTextFile(filename)