title: PHP and jQuery update textbox with checkbox value
body: <p>I have the following functionality I would like to build into a form using jQuery:</p>
  
  <p>I have a list of values:
  Invoice No: 110, Amount: 240.00
  Invoice No: 111, Amount: 399.00
  Invoice No: 112, Amount: 150.00</p>
  
  <p>Next to each row there is a checkbox which is set to checked by default. Right at the bottom there is a textbox with the total 789.00 for the set of data. I would like to update the textbox when one of the checkboxes are de-selected &amp; selected with the total of invoice amounts which checkboxs are checked.</p>
  
  <p>The form will then be submitted to itself with the value of the textbox set.</p>
  
  <p>Any suggestions welcome, as I'm a noob with jQuery.</p>