Why spark plugs can not be displayed?

Hello,

in my spark/plugins installation directory, there are many plugin jar files such as spelling-plugin.jar.

and I copy the jar file to my spark source code path:/src/plugsins .I run this source code in eclipse.

I click spark->plugins, and choose available plugins but I can not find that spelling-plugins displayed in

this column,why?

Who can tell me? Did I use the wrong way to add plugins? Help me!

thanks!

Add the plugin jars in C:\Program Files\Spark\plugins