Connection limit on virtual server and message back to client

For testing, I am using this iRule but it is not working :

when RULE_INIT {

  set ::active_connections 0

  set ::max_connections 2

  set ::html_content "over_limit"

}

when CLIENT_ACCEPTED {

    set over_limit 0

    if {$::active_connections > $::max_connections } {

   set over_limit 1

  } else {

   incr ::active_connections 1

  }

}

when HTTP_REQUEST {

  if {$over_limit}{

    HTTP::respond 200 content $::html_content

    HTTP::close

  }

}

when CLIENT_CLOSED {

  incr ::active_connections -1

}