Filter ajax post request with message to cp1251 with code filtering

gistfile1.aw

function filter($a,$ajax=false)
{
/*
 *Filter text messages created by ajax post request to mysql insertions, also all malicious tags (scripts, frames et cetera are removed)
 */

if ($ajax) $a=iconv('UTF-8','WINDOWS-1251',urldecode($a));

$a=trim($a);
$a=preg_replace('~<script.*>.*</script>~im',NULL,$a);
$a=preg_replace('~<iframe.*>.*</iframe>~im',NULL,$a);
$a=preg_replace('~<FRAME\s[^>]*>~im',NULL,$a);
$a=preg_replace('~</?frameset[^>]*>~im',NULL,$a);
$a=preg_replace('~</?NOFRAMES>~im',NULL,$a);
$a=preg_replace('~<([A-z0-9]+)(\s.+)>(.+)</[A-z0-9]>~i','<\\1>\\3</\\1>',$a);
$a=preg_replace("~\s{2,}~im","\n",$a);
$a=mysql_real_escape_string($a);	

return $a;
}