Using same php file to show form and receive the form's data

Question

I have a php page that generates a form. The action attribute of the form is the page itself. After the user submits the form, the same page is loaded, but this time a POST vari

Answer 1

You might even want to go to the extent of checking whether the data was submitted thru AJAX to differentiate it from a regular form submission:

if ( $_SERVER['X_REQUESTED_WITH']=='XMLHttpRequest' )
  // AJAX