PHP Inform

PHP function that verify if in a string have broken HTML tags

function broken_tags($str) 
{ 
preg_match_all(”/(<\w+)(?:.){ 0,}?>/”, $str, $v1); 
preg_match_all(”/<\/\w+>/”, $str, $v2); 
$open = array_map('strtolower', $v1[1]); 
$closed = array_map('strtolower', $v2[0]); 
foreach ($open as $tag) 
{ 
$end_tag = preg_replace(”/<(.*)/", "“, $tag); 
if (!in_array($end_tag, $closed)) return true; 
unset($closed[array_search($ end_tag, $closed)]); 
} 
return false; 
}