iRule based on domain

I ended with this script, however its not working, i don't get any 403 respond nor accept when it spoof the origin, all i get is connection reset, any suggestions?

    when HTTP_REQUEST {
    if { [HTTP::header exists Origin] } {
        set origin_host [HTTP::header Origin]
    }
}

when HTTP_RESPONSE {
    if { [info exists origin_host] } {
        if { $origin_host contains "mydomain1.com" } {
           pool $HTTP_pool
       } elseif { $origin_host contains "mydomain2.com" } {
           pool $HTTP_pool
            } elseif { $origin_host contains "mydomain3.com" } {
           pool $HTTP_pool
       } else {
    HTTP::respond 403  
    }
    } else {
    HTTP::respond 403
    }
}