JSFiddle - React, Tailwind, and code Playground

HTML

<input type="button" id="button" value="Add input">
<form name = "form" id="form" action="http://peter-ajtai.com/examples/php/post.php" method="POST">
   <ul style="width:670px;padding:0px 0px 30px 0px" id="list">
   </ul>
   <input type="submit" id="submit" value="Submit">
</form>

JavaScript

$("#button").live('click',function() {
   $("#list").append(
       '<li style="height:20px;">' +
         // Removed repetitive ID and made prova an array
       '<input type="text" class="text" name="prova[]" value="prova"></li>'
   ); 
});