title: Prevent different users simultaneously entering a Google Sheet
body: <p>I have created a Google Sheet that many users are using and I have created a script that automatically deletes all the values once the file is opened, so that the user always starts with a clean interface. </p>
  
  <p>It is dangerous of course, when somebody is filling out the sheet and another person goes in and triggers the reset code.</p>
  
  <p>Is there a way to prevent that two users are entering and using a sheet at the same time?</p>