add: if (!uri) uri = getLink(defaultTopic); 
context: function displayTopic(topic) {  if (!topic)    topic = defaultTopic;  var uri = getLink(topic);  loadURI(uri);}
meta: 8395	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/8395/2cd94756a0d86af164afec50f8f35268916b9581/help.js/buggy/extensions/help/resources/content/help.js