title: How to know index of a <tr> inside a <table> with jQuery?
body: <p>I'm now implementing something like <a href="https://stackoverflow.com/questions/1845600/how-to-move-a-tr-up-or-down-within-table-via-jquery">this post</a> (specifically, the effect takes place when the row is clicked)</p>
  
  <p>How do I know what the index of the row is inside the table?</p>