<?php
  require_once 'browser_common.php';
  require_once 'browser_manage_common.php';

  // load session
  $dispparam = $_SESSION['browser']['dispparam'];
    $s = $dispparam['species'];
    $r = $dispparam['revision'];
  $tracks    = $_SESSION['browser']['tracks'][$s][$r];

  $tracknum = $_GET['tracknum'];
  $track = $tracks[$tracknum];
  $optparam = $track['optparam'];

  assert( is_numeric($tracknum) );
  assert( ! is_null($track) );

  $req = $_GET;

  foreach( $req as $key => $val ) {

		if( strlen($val) > 0 ) {
			if( $val == '_default' ) {
        unset( $optparam[urlencode($key)] );
      }
      elseif( substr($key,0,4) == 'disp' && $val == 'on' ) {
        unset( $optparam[urlencode($key)] );
      }
      elseif( substr($key,0,5) == 'apply' ) {
        unset( $optparam[urlencode($key)] );
      }
      elseif( substr($key,0,3) == 'sid' ) {
        unset( $optparam[urlencode($key)] );
      }
      elseif( substr($key,0,8) == 'tracknum' ) {
        unset( $optparam[urlencode($key)] );
      }
      else {
        $optparam[urlencode($key)] = $val;
      }
    }
  }
  $track['optparam'] = $optparam;
  $tracks[$tracknum] = $track;

  // set loaded values to session
	$_SESSION['browser']['tracks'][$s][$r] = $tracks;
	if ( isset( $_SESSION['login'] )) {
		save_optparam_to_trackinformationDB( $s,$r,$track,$optparam );
	}
  header( 'Location: browser.php?' . htmlspecialchars(SID) );
?>