title: Thymeleaf HTML5 long variable issue
body: <p>I am new to Thymeleaf and HTML5.</p>
  
  <p>I have a variable <code>order number</code> of data type <code>long</code>. </p>
  
  <p>There is an input text field in the HTML for searching order number (assigned to <code>order number</code> variable), which always initialise to zero everytime when we load the HTML page.</p>
  
  <p>Also, I am getting the error when I manually empty the filed and submit the form to fetch record from database.</p>
  
  <p>My requirement is to have this field empty because this is an optional field. It can be zero/null/doesn’t contain any value.</p>
  
  <p>Sample Code Snippet: <code>&lt;input type=“text” th:field=${order.ordernumber}&gt;</code></p>
  
  <p>Please advise on how to get this order number variable (<code>long</code> data type) without any default value being set.</p>