How can I transfer pokemon from Diamond to Platinum with Global Trade?

I put a pokemon up in the Global Trade System in order to transfer from Diamond to Platinum (I have no access to a second DS) but my pokemon aren't showing up in the system. No matter how many times I switch around the stats, I only get the same people. Is there a system that refreshes this, so I can see my own pokemon and trade it, or should I stop trying?|||I think it is because they are connected to the same Internet Access Point. Put them up for offer and the next time you are at a friend's house go and see if you can find them in the GTS then. It might also be because you put them up for offer with the same DS. The Internet Connection thing is far more likely, however.|||well i think it really counts about the strength of the WiFi connection