Uploading Gifs and Jpegs

In need of some help and I'm new to ASP.   I can't use one of the uploaders on the market because the client can't install the needed stuff, and plus I have this mostly working.  

I can upload seemingly just about any file, except a JPG.  I only want to allow extensions of GIF, JPG, and JPEG, and I can't figure out for the life of me why this code hangs when uploading a JPG, but GIF is working fine.

This wasn't my original code, but I can't remember where I found it.  I've changed it a bit, but like I said evthing but jpg works.  I know its a lot to sift through, but based on my experience in other web technologies, I would assume its a lot easier than 500 points would sugguest.

Thanks for all your help

Please advise.

Code for the form (choosefile.asp):

<!--#include file="header.asp"-->

      <form action="filePost.asp" enctype="multipart/form-data" method="post" name="f" id="f">
         Pick a file to upload:<br/>
         <input type="file" name="test" size="50" />
         <br />
         <!---input type="radio" name="filename" value="original" checked />
            Use filename from disk
         <br />
         <input type="radio" name="filename" value="userSpecified" />
            Use the following name:
         <input type="text" name="userSpecifiedName" value="" /--->
         input type="hidden" name="userSpecifiedName">
         <input type="hidden" name="filename" value="original">
         <br/>
         Link to: <br/>
         <input type="text" name="linkto" size="50" value="http://">
         <input type="submit" value="Upload Ad" />
      </form>
<!--#include file="footer.asp"-->


Code for the upload page (filepost.asp):


<!--#include file="header.asp"-->

<%
'Adjust this depending on the size of the files you'll
'be expecting; longer timeout for larger files!
Server.ScriptTimeout = 5400

Const ForWriting = 2
Const TristateTrue = -1
CrLf = Chr(13) & Chr(10)

'This function retreives a field's name
Function GetFieldName(infoStr)
      sPos = InStr(infoStr, "name=")
      EndPos = InStr(sPos + 6, infoStr, Chr(34) & ";")
      If EndPos = 0 Then
            EndPos = inStr(sPos + 6, infoStr, Chr(34))
      End If
      GetFieldName = Mid(infoStr, sPos + 6, endPos - _
            (sPos + 6))
End Function

'This function retreives a file field's filename
Function GetFileName(infoStr)
      sPos = InStr(infoStr, "filename=")
      EndPos = InStr(infoStr, Chr(34) & CrLf)
      GetFileName = Mid(infoStr, sPos + 10, EndPos - _
            (sPos + 10))
End Function

'This function retreives a file field's MIME type
Function GetFileType(infoStr)
      sPos = InStr(infoStr, "Content-Type: ")
      GetFileType = Mid(infoStr, sPos + 14)
End Function

'Yank the file (and anything else) that was posted
PostData = ""
Dim biData
biData = Request.BinaryRead(Request.TotalBytes)
'Careful! It's binary! So, let's change it into
'something a bit more manageable.
For nIndex = 1 to LenB(biData)
      PostData = PostData & Chr(AscB(MidB(biData,nIndex,1)))
Next

'Having used BinaryRead, the Request.Form collection is
'no longer available to us. So, we have to parse the
'request variables ourselves!
'First, let's find that encoding type!
ContentType = Request.ServerVariables( _
      "HTTP_CONTENT_TYPE")
ctArray = Split(ContentType, ";")
'File posts only work well when the encoding is
'"multipart/form-data", so let's check for that!
If Trim(ctArray(0)) = "multipart/form-data" Then
      ErrMsg = ""
      ' grab the form boundary...
      bArray = Split(Trim(ctArray(1)), "=")
      Boundary = Trim(bArray(1))
      'Now use that to split up all the variables!
      FormData = Split(PostData, Boundary)
      'Extract the information for each variable and its data
      Dim myRequest, myRequestFiles(9, 3)
      Set myRequest = CreateObject("Scripting.Dictionary")
      FileCount = 0
      For x = 0 to UBound(FormData)
            'Two CrLfs mark the end of the information about
            'this field; everything after that is the value
            InfoEnd = InStr(FormData(x), CrLf & CrLf)
            If InfoEnd > 0 Then
                  'Get info for this field, minus stuff at the end
                  varInfo = Mid(FormData(x), 3, InfoEnd - 3)
                  'Get value for this field, being sure to skip
                  'CrLf pairs at the start and the CrLf at the end
                  varValue = Mid(FormData(x), InfoEnd + 4, _
                        Len(FormData(x)) - InfoEnd - 7)
                  'Is this a file?
                  If (InStr(varInfo, "filename=") > 0) Then
                        'Place it into our files array
                        '(While this supports more than one file
                        'uploaded at a time we only consider the
                        'single file case in this example)
                        myRequestFiles(FileCount, 0) = GetFieldName( _
                              varInfo)
                        myRequestFiles(FileCount, 1) = varValue
                        myRequestFiles(FileCount, 2) = GetFileName( _
                              varInfo)
                        myRequestFiles(FileCount, 3) = GetFileType( _
                              varInfo)
                        FileCount = FileCount + 1
                  Else
                        'It's a regular field
                        myRequest.add GetFieldName(varInfo), varValue
                  End If
            End If
      Next
Else
      ErrMsg = "Wrong encoding type!"
End If

'Save the actual posted file
'If supporting more than one file, turn this into a loop!

'Set lf = server.createObject("Scripting.FileSystemObject")
      'file extension
      sPos = InStrRev(myRequestFiles(0, 2), ".")
      extension = mid(myRequestFiles(0, 2), sPos + 1)
      
      if lcase(extension) = "jpg" or lcase(extension) = "gif" or lcase(extension) = "jpeg" then
            
            Set cn = Server.CreateObject("ADODB.Connection")
            Set rs = Server.CreateObject("ADODB.Recordset")

            sql = "select max(id) from adverts "

            cn.Open connectString
            rs.Open sql, cn, 1
            
            if isnumeric(rs.fields(0)) then
                  newFileNum=rs.fields(0)+1
            else
                  newFileNum=1
            end if
            finalFileName="ad" & newFileNum & "." & extension
            FilePath = "./images/ad" & newFileNum & "." & extension
            response.Write("'" & filepath & "'")
            
            rs.close
            cn.close
            
            'SavePath = Server.MapPath(FilePath)
            'Set SaveFile = lf.CreateTextFile(SavePath, True)
            'SaveFile.Write(myRequestFiles(0, 1))
            'SaveFile.Close
            
            'insert the ad
            'Set objConn = Server.CreateObject("ADODB.Connection")
      
            ' -- Open the Connection
            'objConn.Open connectString
            'sql = "insert into adverts (aduserid,filename,linkto) values (" _
            '        & session("aduserid") & ", '" & finalFileName & "', '" & myRequest("linkto") & "')"
          ' - Execute
            'response.Write(sql)
          'objConn.Execute (sql)
   
          'objConn.Close
          'set objConn = Nothing
            
            
            

      else
            ErrMsg = "The advertisement must be a JPG or GIF."
            
      end if
      
      
'IIS may hang if you don't explicitly return SOMETHING.
'So, redirect to another page or provide some kind of
'feedback below...
%>




<% If ErrMsg = "" Then %>
      Your advertisement has been uploaded.  Don't forget to <a href="purchase.asp">purchase time</a> for it to display.
<% Else %>
      <%= ErrMsg %>
      Please <a href="javascript:history.go(-1);">go back</a> and correct the problem.
<% End If %>

<!--#include file="footer.asp"-->