text: function injectScript(file, node) {
      var s = document.createElement('script');
      var h = document.documentElement;
      s.setAttribute('type', 'text/javascript');
      s.setAttribute('src', file);
      h.appendChild(s);
  }
  
  injectScript( chrome.extension.getURL('inject_script.js'), 'body');
  window.addEventListener('message', function(event) {
      if (event){
      chrome.runtime.sendMessage(event.data);
      }
  });
  