PRB: Doctype Parsing Behavior in Visual InterDev

ID: Q175324

The information in this article applies to:

SYMPTOMS

The following error occurs when browsing an Active Server Pages (ASP) file:

Response object error 'ASP 0156'

Header Error <your asp file>, line 3 The HTTP headers are already written to the client browser. Any HTTP header modifications must be made before writing page content.


CAUSE

The following conditions cause the error to occur:

Every time the file is saved in Visual InterDev the FrontPage Server Extensions parse the file and add the following line to the top of the file (the local copy does not change, so you have to get working copy to see the changes): 

   "<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">"
With the above line added to the file, the response properties mentioned above are now set after the HTTP header has been written to the client browser.


RESOLUTION

Remove the WebBot.

-or-

Edit the ASP file in NotePad and remove the "DOCTYPE" line.

-or-

Don't use "response.expires" or "Response.buffer".


STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article.


MORE INFORMATION

Steps to Reproduce Behavior

  1. Create a new .htm file in a Visual InterDev project.


  2. Open the .htm file in Microsoft FrontPage97 (Visual InterDev edition).


  3. Add the Timestamp bot to the .htm file. Save and close.


  4. Rename the .htm file extension to .asp and open the .asp file in the default editor.


  5. Add the following code to the third line (after <%@ LANGUAGE...) in the file <%response.expires=0%>. Save and preview the file.


The error described above appears.

Get a working copy of the file and select Use Master Copy when prompted.

The first line of the file now contains the <doctype...> instead of <%@ language =...>


REFERENCES

For the latest Knowledge Base articles and other support information on Visual InterDev and Active Server Pages, see the following page on the Microsoft Technical Support site:

http://support.microsoft.com/support/vinterdev/

Additional query words: 


Keywords          : kbExtension kbFrontPage kbServer kbVisID100 kbGrpASP 
Version           : WINDOWS:1.0
Platform          : WINDOWS 
Issue type        : kbprb

Last Reviewed: July 13, 1999