title: How to sum the values of checked checkboxes from an HTML form in a PHP script
body: <p>I am having some dificulties with a PhP script that is sent data from an HTML form.</p>
  
  <p>Basically on the form I have multiple checkboxes each with a numeric value.  I want the PHP to output the sum of the values from only the checked checkboxes.  </p>
  
  <p>So if checkbox 1 had a value of 10, 2, a value of 15, and 3 a value of 20 and the user checked 1 and 3 and clicked submit it would output 30.</p>
  
  <p>Any help appreciated.</p>
  
  <p>Thank you!</p>