Applet problem please help

Hi,

I am trying to run an applet, called from an html page. I have java and netbeans installed on my computer and the applet compiles ok. However, when I first tried to run the applet in the html page it said the applet was not inited and it failed when loading, so I installed JVM on my computer, now when I call it from the html page it says Java plug-in detected JRE collison, so I'm guessing I didn't need to install the JVM and now there are two things that can read it but they now conflict because I download it?

What other things can cause an applet not to lead in the browser?