1 - secure - sécuriser une chaine ou un tableau contre le XSS
function secure($var,$level=0){
    // $level=0 > returns text only (no html or script), 1 > text + html (no script), 2 > all content secured with entities
    if (is_array($var)){foreach ($var as $index=>$v){$var[$index]=secure($v,$level);}}
    else if (is_string($var)){
        if ($level==0){$var=strip_tags($var);}
        else if ($level==1){$var=preg_replace('#on[a-z]+ ?= ?["\'].*?["\'](?=[ />])|</?script>|javascript:#i','',$var);}
        else {$var=htmlspecialchars($var);}
    }
    return $var;
}