Customizing the placeholder text in Google Custom Search input

readme.txt

In Sample Script, the added lines are 11 and 12.

Sample Script

<script>
  (function() {
    var cx = '008259309430927337174:3jjrzypsqka';
    var gcse = document.createElement('script');
    gcse.type = 'text/javascript';
    gcse.async = true;
    gcse.src = 'https://cse.google.com/cse.js?cx=' + cx;
    var s = document.getElementsByTagName('script')[0];
    s.parentNode.insertBefore(gcse, s);
  })();
window.onload = function(){
document.getElementById('gsc-i-id1').placeholder = 'Search this website ...';
};
</script>
<gcse:search></gcse:search>