Can't view youtube using proxy. Get message. "either have JavaScript turned off " etc. OS X all software OK

Sorry, I tried to squeeze as much as I could into the limited question field. I'm in Thailand which continues to block youtube. I can get to it via a proxy server. I can get that far, and browse, but no further. When I try to choose a particular video, I get the warning, "Hello, you either have JavaScript turned off or an old version of Macromedia's Flash Player." message. Not true! All my software works fine. All my preferences are OK. My problem only shows up when I use proxy servers. Admittedly, I'm not especially well informed in their proper use. What am I missing? Do I have to tell the proxy servers to allow the videos? Or change their preferences? Do I need to pay for some form of elite proxy server? Thanks!