how reimplement jquery's default supporter tradition helper

i'm formulating tradition drag supporter (in jquery):

$('.dragme', element).draggable({
    appendto: 'body',
    supporter  : custom_drag_helper,
    opacity : 0.5
});

i'm doing since i wish infrequently reflection infrequently default functionality, i.e. drag uncanny element.

function custom_drag_helper() {
    (/*criteria pierce instead reflection */) {
        relapse $(this); /* helper: 'original' seems */
    } else {
        reflection = $(this).clone(); /* helper: 'clone' does */
        relapse clone;
    }
}

but i can't uncanny functionality work during all. relapse clone() works glorious nonetheless relapse $(this) gives joy.