add: if (aCommand == "cmdEditCopy") { return this.mPropsTree.view.selection.count > 0; } 
context:   isCommandEnabled: function(aCommand)  {    return false;  },
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/cf2f115c6a434d17c7b187d01dcf1fbb049dc504/styleRules.js/clean/extensions/inspector/resources/content/viewers/styleRules/styleRules.js