title: How to create an alert message in Google app script while deploying a web app?
body: <p>I am trying to create a web app using Google app script, that if you press a button, you may get an alert message.</p>
  
  <p>In the home.gs file I tried this :</p>
  
  <pre><code>function let_user_decide()
  {
  Browser.msgBox('Greetings', 'Press Yes or No?', Browser.Buttons.YES_NO);
  };
  </code></pre>
  
  <p>unfortunately I keep getting this when I press the button when I should get the alert message :</p>
  
  <blockquote>
    <p>Exception: Cannot call Browser.inputBox() from this context.</p>
  </blockquote>
  
  <p>Important to mention : my script is using Google spreadsheet but the msgBox should appear in the webapp! In addition, I use HTML</p>
  
  <p>Any idea what am I doing wrong? And how can I fix it?</p>