Virtual server with two different web servers

I have setup an irule, and blank stream profile, but it is not changing the URL using the irule I have below, I am sure it is something I am doing wrong.

when HTTP_REQUEST {

Explicitly disable the stream profile for each request so it doesn't stay

enabled for subsequent HTTP requests on the same TCP connection.

STREAM::disable

}

when HTTP_RESPONSE {

Apply stream profile against text responses from the application

if { [HTTP::header value Content-Type] contains "text" }{

  STREAM::expression {@insideserver.domain.com@outsidserver.domain.com@}



   Enable the stream profile

  STREAM::enable

}

}