title: jQuery add row before fourth to last row
body: <p>I have an invoice table. The last four rows are as follows, starting from last: Grand Total, Tax, Subtotal, Add a line link.</p>
  
  <p>So I need to add a row before the "Add a link link row". </p>
  
  <p>This thread <a href="https://stackoverflow.com/questions/171027/add-table-row-in-jquery">Add table row in jQuery</a> shows how to add a row after the last row. I just need to modify it, to add a row before the fourth to last row.</p>