Google Custom Search Engine always let search with "intitle:"

cse_intitle.html

<gcse:searchresults-only gname="results"></gcse:searchresults-only>

cse_intitle.js

var term = "search_term";

var myCallback = function() {

  if (document.readyState == 'complete') {
    var searchResult = google.search.cse.element.getElement("results");
    searchResult.execute(term);
  } else {
    google.setOnLoadCallback(function() {
      var searchResult = google.search.cse.element.getElement("results");
      searchResult.execute(term);
    }, true);
  }
};

window.__gcse = {
  parsetags: 'onload',
  callback: myCallback
};