Fatal error: Only variables can be passed by reference

Some versions of php can give this error on line 52

      foreach ($filter['value'] as $v) {
$html.=views_build_view('embed', views_get_view($v), $args, $view->use_pager, $view->nodes_per_page);
      }

change with

      foreach ($filter['value'] as $v) {
      $a1=views_get_view($v);
      $a2=$args;
      $a3=$view->use_pager;
      $a4=$view->nodes_per_page;
	$html.=views_build_view('embed', $a1, $a2, $a3, $a4);
      }

sorry, i'm not a php programmer