rem: var folderPaneUIVersion = pref.GetIntPref("mail.ui.folderpane.version"); 
add: var folderPaneUIVersion = pref.getIntPref("mail.ui.folderpane.version"); 
context: function UpgradeFolderPaneUI(){  var folderPaneUIVersion = pref.GetIntPref("mail.ui.folderpane.version");  if (folderPaneUIVersion == 1) {    var folderUnreadCol = document.getElementById("folderUnreadCol");    folderUnreadCol.setAttribute("hidden", "true");    var folderTotalCol = document.getElementById("folderTotalCol");    folderTotalCol.setAttribute("hidden", "true");    pref.SetIntPref("mail.ui.folderpane.version", 2);  }}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/f1f4e0d7a57ab7bc6d826daa2e6141efd69e1dce/msgMail3PaneWindow.js/clean/mailnews/base/resources/content/msgMail3PaneWindow.js