title: Google Apps Script - Validating Dates in Form
body: <p>It seems to me that GAS has no feature to do validation besides 'required' in Google Forms.</p>
  
  <p>I have 2 dates. Start Date &amp; End Date.
  I'm figuring if there's any way to check and make sure end date is not earlier than start date.</p>
  
  <p>It seems like using UI or HTML form is the way to go. But I just want to see if anyone has other alternatives?</p>
  
  <p>If the answer is no, then I'll probably use this method >
  <a href="https://stackoverflow.com/questions/19231531/form-validation-before-submission">Form Validation Before Submission</a></p>