Filter users by a custom field?
To get a user by a custom field, you would need to create a ElementCriteriaModel like this:

$criteria = craft()-&gt;elements-&gt;getCriteria(ElementType::User);
$criteria-&gt;fieldName = craft()-&gt;request-&gt;getPost('fieldName');

$users = $criteria-&gt;find();


you could then loop over $users and use getAttributes() to get the user data, and if you need the attribute names use attributeNames() if you need the users fields.