Call Function from Link Click

You basically want to create a menu item of type MENU_CALLBACK. Something like this in hook_menu...

function my_module_menu() {
  $items['path/to/%/complete'] = array(   // assuming you want to make this dynamic
    'title' => 'Complete',
    'page callback' => 'my_module_complete_function',
    'page arguments' => array(2),   // references %, i'm assuming this is all dynamic
    'access arguments' => array('access content'),  // don't do this, whatever permission you want goes here
    'type' => MENU_CALLBACK
  );
  $items['path/to/%/delete'] = array(
    'title' => 'Delete',
    'page callback' => 'my_module_delete_function',
    'page arguments' => array(2),
    'access arguments' => array('access content'), // whatever see above
    'type' => MENU_CALLBACK    
  );
  return $items;
}

// ... skip ahead to where you put your function
function my_module_delete_function($identifier_for_what_percent_is) {
  return 'blah blah blah blah blah'; //text to return to display
}

If you wanted to go about it a different way you could make the path something like path/to/%/% and pass in array(2,3). And then the third option would be like an $op variable for one function that you call instead of two. I like to split my functions up personally.

Edit: had this open for like an hour before posting.