rem: node.setAttribute("hidden", "true"); 
add: node.setAttribute("collapsed", "true"); 
context: function HideMessageHeaderPane(){  msgPaneData.ViewAllHeadersToolbar.setAttribute("hidden", "true");  msgPaneData.ViewAllHeadersBox.setAttribute("collapsed", "true");  var node = document.getElementById("headerPart1");  if (node)    node.setAttribute("hidden", "true");  node = document.getElementById("headerPart2");  if (node)    node.setAttribute("hidden", "true");  node = document.getElementById("headerPart3");  if (msgPaneData.UserAgentToolbar)    msgPaneData.UserAgentToolbar.setAttribute("hidden", "true");}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/28bbf61434de6d11cac91a0c93b691b3e4ff20cf/msgHdrViewOverlay.js/buggy/mailnews/base/resources/content/msgHdrViewOverlay.js