Google Play Store Desktop Download

Can someone please help? I am on FF 18, Windows XP and the latest Java (1.7.0_11).After spending many hours searching for and reading posts about FF blocking Java I fully understand the reasoning for this and it's fine by me BUT I do want to view/use java on trusted sites. The article, -US/kb/how-to-use-java-if-its-been-blocked , seemed clear and simple enough BUT when I tried doing this on the Oracle Java test page, like others, I did not get any option to 'click to Play'. There was no red icon in the address url box (to click on) but there was a yellow pop up strip containing a blue icon on the left, the notice that a plugin was required and a button to install it. Clicking on the blue icon did not bring up any 'click to Play' option and this icon does not appear in the address url box. Clicking on the install button does only take me back to the download page at Oracle (and we can go on ad infinitum on this route).