title: Control what variables appear in $_POST
body: <p>I have a form with several  elements. When they submit the form, I want to use $_POST to see what values have been selected. Now, is it possible to make it so that they only actually get "posted" if a selection is made that is not 0 since since 0 is the default value and if it is 0 they are not actually selecting anything? Or do I have to go through the entire $_POST array to see which ones are non zero? </p>
  
  <p>I don't know which elements I want to access in the $_POST array before hand. I only want my form submission page (the page that goes in the action="" part) to be aware of fields that have non zero selections. Is this possible? Thanks!</p>