Pops up a window querying the user for proxy authentication information if necessary to use. This should bypass the proxy support built-in to the web browser. This param is experimental, please report any problems you experience with it to WebMaster, Inc. at support@webmaster.com.
Examples:
In a web page:
<param name="useproxyauthentication" value="true">
In a param file:
useproxyauthentication=true