How to reset user's password

--php opening--

$tempPswd =  rand(2593, 4999);
$newPswd = "cimb".$tempPswd;
$memObj = $_mxPub->factory(null,MX_OBJECT_MEMBER);
$memArc = $memObj->getAll(array('username' => $username));
foreach ($memArc as $member) {
 $usrMail = $member->email;
 $usrName = $member->username;
 echo "Your new password had been send to your email ".$member->email;
 $member->resetUsernamePassword($member->username,$newPswd);
}

--php closing--