add:  if (!('elementIDs' in this.pageData[aPageTag])) this.pageData[aPageTag].elementIDs = new Object();  if (!('userData' in this.pageData[aPageTag])) this.pageData[aPageTag].userData = new Object();  
context:     getPageData: function (aPageTag)    {      if (!(aPageTag in this.pageData))        this.pageData[aPageTag] = { };      return this.pageData[aPageTag];    },
meta: 10234	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/10234/e574d3ce97487b5e3cf094d3df0cb8ea87311536/nsWidgetStateManager.js/clean/toolkit/content/nsWidgetStateManager.js