rem: if (iframe.getAttribute("src") != "about:blank") iframe.setAttribute("src", "about:blank"); 
add: iframe.setAttribute("src", "chrome: 
context: function displayResult(){  var resultRange = Evaluator.document.createRange();  resultRange.selectNode(Evaluator.document.documentElement);  var result = resultRange.toString();  if (result)    gConsole.mCService.logStringMessage(result);    // or could use appendMessage which doesn't persist  var iframe = document.getElementById("Evaluator");  if (iframe.getAttribute("src") != "about:blank")    iframe.setAttribute("src", "about:blank");}
meta: 9421	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/9421/111c024893fb4a3d33f80ccbf91727515c5667eb/console.js/buggy/xpfe/components/console/resources/content/console.js