title: Insert null value into a text input
body: <p>I'm pretty sure it's not possible to do this but I'm still asking for it.</p>
  
  <p>Is there a way for a user to insert a null (or an undefined) value into an html text input?</p>
  
  <p>I need to distinguish between a null value and an empty string and I would like to allow the user to set this value into a single input.</p>
  
  <p>For what I can see across the web, the standard solution to this problem is to match the text input with a checkbox that tell if the value is null or not.  From my understanding, the limitation is linked to the fact that the textbox can hold an empty string but not a null value so that's why I think it's not possible to do exactly what I want.</p>