adding to web.config in a web service?

hi there.

i have a little function that gets html data from an internal site.  when i was testing it as a regular web app, i just added the following section to my web.config file under the <configuration> section:

<setting><httpWebRequest useUnsafeHeaderParsing="true"></setting>

and it worked just fine.

now i've changed my test app to a web service.  i'm trying to add the same setting in my web.config but it doesn't like it.  i've tried adding to all  the different sections but it doesn't seem to like it. 

any suggestions would be appreciated