SOURCE

window.onload = function() {
  var oQ = document.getElementById('q');
  var oUl = document.getElementById('ul1');

  oQ.onkeyup = function() {
    if (this.value != '') {
      var oScript = document.createElement('script');
      //这两个远程路径均有效
      //https://sp0.baidu.com/5a1Fazu8AA54nxGko9WTAnF6hhy/su?wd=a&cb=ccc
      //http://suggestion.baidu.com/su?wd=
      oScript.src = "https://sp0.baidu.com/5a1Fazu8AA54nxGko9WTAnF6hhy/su?wd=" + this.value + '&cb=hu';
      document.body.appendChild(oScript);
    } else {
      oUl.style.display = 'none';
    }
  }
}

function hu(data) {

  var oUl = document.getElementById('ul1');
  var html = '';
  if (data.s.length) {
    oUl.style.display = 'block';
    for (var i = 0; i < data.s.length; i++) {
      html += '<li><a target="_blank" href="http://www.baidu.com/s?wd=' + data.s[i] + '">' + data.s[i] + '</a></li>';
    }
    oUl.innerHTML = html;
  } else {
    oUl.style.display = 'none';
  }

}

<input type="text" id="q" />
<ul id="ul1">
</ul>

#q {
  width: 300px;
  height: 30px;
  padding: 5px;
  border: 1px solid #f90;
  font-size: 16px;
}

#ul1 {
  border: 1px solid #f90;
  width: 310px;
  margin: 0;
  padding: 0;
  display: none;
}

li a {
  line-height: 30px;
  padding: 5px;
  text-decoration: none;
  color: black;
  display: block;
}

li a:hover {
  background: #f90;
  color: white;
}