title: Display custom message after submitting a Google Form
body: <p>I have a Google Form that allows user to enter their information. After they submit the form, the data is inserted to a Google spreadsheet as a new row.</p>
  
  <p>However I want to show a dynamic message right after the form is submitted, overriding the original "thank you" message. The new message would display the information they just filled in, with an number assigned to him.</p>
  
  <p><strong>For example, Mary filled in her data and submit the form. Since Mary is the 5th person to submit this form, the message shows her number as 5.</strong></p>
  
  <p>Is there any way to achieve this? I have been studying Google App Script and HTML service but I am not sure if this is the correct way.</p>
  
  <p>Please note that we have already using email to send out this message for several years however user strongly suggest that showing their ID right after form submission would make lots of things much easier.</p>
  
  <p>Thank you very much!</p>
  
  <h2>Update</h2>
  
  <p>I have been working on it and now I am able to make a web page that inserts a new row to a spreadsheet. But another question: How to publish the web page? <strong>When I open the "/dev" link it works fine; However when I open the "/exec" link it says cannot find "Index.html" and I am sure there is a file called Index.html.</strong></p>