$ (function(){

    $('#email-field').focus(function() {
        $('#email-field').addClass('focus');
    })
    .focusout(function() {
        if($('#email-field').val() == '') {
            $('#email-field').removeClass('focus');
        }
    });

    $('#password-field').focus(function() {
        $('#password-field').addClass('focus');
    })
    .focusout(function() {
        if($('#password-field').val() == '') {
            $('#password-field').removeClass('focus');
        }
    });

});