title: Auto Calculate form fields value using jQuery calculation plugin
body: <p>I am building a form that will automatically calculate the values entered by a user ideally using jQuery/javascript, i am not sure how to do this but have a general idea of the logic required (i am no expert so feel free to correct me) - I have created a dummy image to help explain what I am trying to do.</p>
  
  <p><a href="http://i.stack.imgur.com/WScNO.png" rel="nofollow">http://i.stack.imgur.com/WScNO.png</a></p>
  
  <p>I have a single form, which has many input fields automatically calculate the total amount for each table provided it has been selected.
  Using jQuery - I would expect the logic to be something like -
  i) Find the input field element
  ii) Find all the text fields within the table that have a value
  iii) Add these together and display in the 'total' form field</p>
  
  <p>While i'm ok on the PHP, javascript is something I still get confused with at times - I would appreciate any help on doing this, and if possible a quick overview to help me learn from the code.</p>
  
  <p>Thanks in advance</p>