rem: collapsedNode.removeAttribute("collapsed"); expandedNode.setAttribute("collapsed", "true"); 
add: collapsedNode.collapsed = false; expandedNode.collapsed = true; 
context: function ToggleHeaderView (){  var expandedNode = document.getElementById("expandedHeaderView");  var collapsedNode = document.getElementById("collapsedHeaderView");  var toggleHeaderView = document.getElementById("msgHeaderView");  if (gCollapsedHeaderViewMode)  {              gCollapsedHeaderViewMode = false;    // hide the current view    hideHeaderView(gCollapsedHeaderView);    // update the current view    UpdateMessageHeaders();        // now uncollapse / collapse the right views    expandedNode.removeAttribute("collapsed");    collapsedNode.setAttribute("collapsed", "true");  }  else  {    gCollapsedHeaderViewMode = true;    // hide the current view    hideHeaderView(gExpandedHeaderView);    // update the current view    UpdateMessageHeaders();        // now uncollapse / collapse the right views    collapsedNode.removeAttribute("collapsed");    expandedNode.setAttribute("collapsed", "true");  }    if (gCollapsedHeaderViewMode)    toggleHeaderView.setAttribute("state", "true");  else    toggleHeaderView.setAttribute("state", "false");}
meta: 5872	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/5872/7b10439c40b4254072b774f5f2ee3fb15c693ade/msgHdrViewOverlay.js/clean/mailnews/base/resources/content/msgHdrViewOverlay.js