title: Calculate total amount with VAT percentage inclusive
body: <p>I have built an <a href="http://jsfiddle.net/Manna/CBk5a/5/" rel="nofollow"><em>editable table</em></a>. There are two rows, one editable with <em>Textarea</em> and the other one editable with <em>Input number</em>. If you click on the column number, you can change the amount and you get automatically the Total sum. </p>
  
  <p>There is also the possibility to clone new rows editable.</p>
  
  <p>I am looking now on how to calculate the percentage (vat 21%) that automatically gives the TOTAl in my last row. I was looking for some examples but i have not found any.</p>
  
  <p>As you can see in my <a href="http://jsfiddle.net/Manna/CBk5a/5/" rel="nofollow">example</a> there  is a function which provide to calculate the total summing my <code>ID="sum"</code> in the rows. </p>
  
  <p>My problem is which function i need to use to calculate the 21% VAT that then automatically gives me the new TOTAL in the last row with this percentage inclusive? </p>
  
  <p>Hope the explanation is clear. <a href="http://esempi.gabrieleromanato.com/jquery/jquery-totale-percentuale-sconto/" rel="nofollow">This</a> is only one example suitable i have found  but i can not apply in my case.</p>