Trying to use this vb6 program to upload a file to a server, and ther server is giving me this error.

"Not supported Content-Disposition"



Here is the code

Code:
Option Explicit
'This code uploads a file to an ASP script using http post
'You need to add a reference to Microsoft XML 3.0 to the project.
'Get this from http://msdn.microsoft.com/xml

Private Sub cmdSubmit_Click()
Dim strText As String
Dim strImage As String
Dim s$
Dim strBody As String
Dim aPostData() As Byte
Dim strFileName1 As String
'Dim strFileName2 As String
Dim oHttp As XMLHTTP
Dim nFile As Integer

'make use of the XMLHTTPRequest object contained in msxml.dll
Set oHttp = New XMLHTTP

'read the whole text file
strFileName1 = InputBox("Text File Name:", "Upload a file", "C:\Documents and Settings\rthomas\Desktop\upload.txt")
nFile = FreeFile
Open strFileName1 For Binary As #nFile
strText = String(LOF(nFile), " ")
Get #nFile, , strText
Close #nFile

'read a GIF file
'strFileName2 = InputBox("Image File Name:", "Upload a file", "c:\temp\test.gif")
'nFile = FreeFile
'Open strFileName2 For Binary As #nFile
'strImage = String(LOF(nFile), " ")
'Get #nFile, , strImage
'Close #nFile

'fire of an http request
'adapt path in next line
oHttp.Open "POST", "http://****************", False
oHttp.setRequestHeader "Content-Type", "multipart/form-data, boundary=AaB03x"

'assemble the body. send one field and two files
strBody = _
   "--AaB03x" & vbCrLf & _
   "Content-Disposition: form-data; name=""field1""" & vbCrLf & vbCrLf & _
   "test field" & vbCrLf & _
   "--AaB03x" & vbCrLf & _
   "Content-Disposition: attachment; name=""FILE1""; filename=""" & strFileName1 & """" & vbCrLf & _
   "Content-Type: text/plain" & vbCrLf & vbCrLf & _
   strText & vbCrLf & _
   "--AaB03x--"
   
'must convert to byte array because of binary zeros
aPostData = StrConv(strBody, vbFromUnicode)

'send it
oHttp.send aPostData

'check the feedback
Debug.Print oHttp.responseText

End Sub

Why do you think I'm getting this error? THanks in advanced.