Download DWG files on asp classic

I need download files from folder on the server.

I have tried this code in ASP Classic, but when the file is DWG the download not working.

I don't have error, this code downloading all files type is out for DWG files.

Can anybody help me?

Thanks in advance.

My code below.

getfile.asp

<%
Function BaseName(byVal Path)
Dim Pos
    Path = Replace(Path,"/","\")
    Pos  = InStrRev(Path,"\")
    If Pos>0 then 
        BaseName = Mid(Path,Pos+1)
    Else
        BaseName = Path
    End if
end function

Function ReadFile(FileName)
Dim Stream , Path
    On error resume next
        Path = Server.MapPath(FileName)
        If Err.Number<>0 then Path = FileName
    On error goto 0
    Set Stream = Server.CreateObject("ADODB.Stream")
    Stream.Type=1
    Stream.Open()
    Stream.LoadFromFile Path
    Stream.Position=0
    ReadFile = Stream.Read()
    Stream.Close()
    Set Stream = Nothing
End Function

' Timeout
Server.ScriptTimeout=6000
if Len(Trim(request.querystring("file"))) > 0 then
    file = server.mappath(request.querystring("file")) 
else
    Response.Write("file not found")
    Response.end
end if
response.ContentType="application/octet-stream"
response.AddHeader "Content-Disposition", "attachment; filename=" & BaseName(file)
Response.BinaryWrite ReadFile(File)
Response.End
%>

default.asp

    <script language="JavaScript" type="text/javascript">
    function doDownload(file1, file2, frmName)
    {
      var ifrmObj = document.getElementById((frmName && frmName.length > 0) ? frmName : "dwnFrm1");
      ifrmObj.src = "";
      ifrmObj.src = "getFile.asp?file=" + file1;

      if (!file2 || file2.length <= 0) return;

      // Timeout
      window.setTimeout("doDownload('" + file2 + "', '', 'dwnFrm2');", 3000);
    }
    </script>

    <body bgcolor="#EAEFFF">

    <iframe id="dwnFrm1" style="display: none;"></iframe>
    <iframe id="dwnFrm2" style="display: none;"></iframe>

    extDWG = right(directoryfile.Name, 3)
    if extDWG = "dwg" then           
       response.write ("<a href=""javascript:void(0);"" onclick=""doDownload('/MyFolder/" & Server.HTMLencode(folder) & "/"& Server.HTMLencode(directoryfile.Name) &"', '/MyFolder/" & Server.HTMLencode(folder) & "/X-cart.dwg');"">")    
    else    
       response.write ("<a href=""/MyFolder/" & folder & "/"  & directoryfile.Name &""">")    
    end if

Solution

You need to add the mime type for dwg files on the server.

Uncommon file extensions often dont have an associasion.

In older IIS (version 6/7) you right click on the server in IIS manager and choose properties and then click the MIME Types button. Here you need to add a record for .dwg files with the correct mime type.
In IIS 8 you click on the sitename in IIS manager, and select MIME types. And then add in the same manner, as explained below:

Press new and depending on extension type and in your case my guess after a short google search would be that .dwg should have application/acad as mime type.

Hope this helps.