persistent connection

Hello all,
attention bad english ahead! ;-)

I'm writing a tool which queries the RIPE DB to find out the location of 
some IP adresses.
When I query the database with a string like "84.149.135.10/16\r\n", i 
get a correct response and the tcp/ip connection will be closed by RIPE.
But because I've to query some more IPs, i would like to let the 
connection open.
As i read in the RIPE DB manual there is the "-k" flag which should tell 
the DB letting the connection open until I send an empty query.
In telnet it works fine, but not in my tool.
In my tool i'm sending a string like "-k 84.149.135.10/16\r\n" (in 
telnet i wrote "-k 84.149.135.10/16" + <return>).
The DB output looks like this:

> % This is the RIPE Whois query server #1.
> % The objects are in RPSL format.
> %
> % Note: the default output of the RIPE Whois server
> % is changed. Your tools may need to be adjusted. See
> % http://www.ripe.net/db/news/abuse-proposal-20050331.html
> % for more details.
> %
> % Rights restricted by copyright.
> % See http://www.ripe.net/db/copyright.html
>
> % Note: This output has been filtered.
> %       To receive output for a database update, use the "-B" flag.
>
> % Information related to '84.136.0.0 - 84.191.255.255'
>
> inetnum:      84.136.0.0 - 84.191.255.255
> netname:      DTAG-DIAL20
> descr:        Deutsche Telekom AG
> country:      DE
> admin-c:      DTIP
> tech-c:       DTST
> status:       ASSIGNED PA
> remarks:      
> ******************************************************************
> remarks:      * Abuse Contact: http://www.t-com.de/ip-abuse in case of 
> Spam,   *
> remarks:      * Hack Attacks, Illegal Activity, Violation, Scans, 
> Probes, etc. *
> remarks:      
> ******************************************************************
> mnt-by:       DTAG-NIC
> source:       RIPE # Filtered
>
> person:       DTAG Global IP-Addressing
> address:      Deutsche Telekom AG
> address:      D-90492 Nuernberg
> address:      Germany
> phone:        +49 180 5334332
> fax-no:       +49 180 5334252
> e-mail:       ripe.dtip at telekom.de
> nic-hdl:      DTIP
> mnt-by:       DTAG-NIC
> source:       RIPE # Filtered
>
> person:       Security Team
> address:      Deutsche Telekom AG
> address:      Germany
> phone:        +49 180 5334332
> fax-no:       +49 180 5334252
> e-mail:       abuse at t-ipnet.de
> nic-hdl:      DTST
> mnt-by:       DTAG-NIC
> source:       RIPE # Filtered
>
> % Information related to '84.128.0.0/10AS3320'
>
> route:        84.128.0.0/10
> descr:        Deutsche Telekom AG, Internet service provider
> origin:       AS3320
> member-of:    AS3320:RS-PA-TELEKOM
> mnt-by:       DTAG-RR
> source:       RIPE # Filtered
>
>
> % This is the RIPE Whois query server #1.
> % The objects are in RPSL format.
> %
> % Note: the default output of the RIPE Whois server
> % is changed. Your tools may need to be adjusted. See
> % http://www.ripe.net/db/news/abuse-proposal-20050331.html
> % for more details.
> %
> % Rights restricted by copyright.
> % See http://www.ripe.net/db/copyright.html
>
> %ERROR:106: no search key specified
> %
> % No search key specified

Thx and greetings
~Sepp