title: Setting a Google Sheets document cells to read-only
body: <p>I am trying to find a way to protect a Google Sheets spreadsheet document from being modified by the owner. In other words, I want to make the cells of my Google Sheets spreadsheet to be read-only. </p>
  
  <p>How can I create a script, assigned to a button, that would accomplish this? </p>
  
  <p>Specifically, I need two features:</p>
  
  <p>1) Make the sheet read-only.
  <br>
  2) Modify a specific cell, then make the sheet read-only again.</p>