php function check password strenght

function CheckPassword($pwd)
{
    $strength = array("Blank","Very Weak","Weak","Medium","Strong","Very Strong");
    $score = 1;
    if (strlen($pwd) < 1){
        return $strength[0];
    }
    if (strlen($pwd) < 4){
        return $strength[1];
    }
    if (strlen($pwd) >= 8){
        $score++;
    }
    if (strlen($pwd) >= 10){
        $score++;
    }
    if (preg_match("/[a-z]/", $pwd) && preg_match("/[A-Z]/", $pwd)) {
        $score++;
    }
    if (preg_match("/[0-9]/", $pwd)) {
        $score++;
    }
    if (preg_match("/.[!,@,#,$,%,^,&,*,?,_,~,-,£,(,)]/", $pwd)) {
        $score++;
    }
    return($strength[$score]);
}