rem: var target = event.originalTarget; item = target.parentNode.parentNode; 
add: var target = event.originalTarget; var item = target.parentNode.parentNode; 
context: function attachmentTreeClick(event){     // we only care about button 0 (left click) events    if (event.button != 0) return;    if(event.detail == 2) // double click    {    var target = event.originalTarget;		item = target.parentNode.parentNode;		if (item.localName == "treeitem")    {			var commandStringSuffix = item.getAttribute("commandSuffix");      var openString = 'openAttachment' + commandStringSuffix;      eval(openString);    }    }}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/84422dcfdea22dd217f851250669f44f5ab494a9/msgHdrViewOverlay.js/buggy/mailnews/base/resources/content/msgHdrViewOverlay.js