title: How to prefill Google form checkboxes?
body: <p>I have looked at the question "<a href="https://stackoverflow.com/questions/20108511/is-it-possible-to-prefill-a-google-form-using-data-from-a-google-spreadsheet">Is it possible to 'prefill' a google form using data from a google spreadsheet?</a>" and the code provided in the answer (thanks Mogsdad) works well for text type Google form questions. My question is:
  Is it possible to prefill a checkbox type Google form question? </p>
  
  <p>For example, if I have an existing spreadsheet with an entry for "Names" and one of the entries is "Fred, Barney" would it be possible, via coding, to have a form prefill with the checkboxes ticked for "Fred" and "Barney" under a "Names" checkbox type Google form question?</p>
  
  <p>Thanks,
  Greig</p>