<%= link_to_function "Fermer","close(event)" %>
produce the html :
Fermer
function close(event){
Event.stop(event);
elt=Event.element(event);
elt.up('table.card').remove();
}
works
<%= link_to_function "Fermer", "Event.stop(event);$(this).up('table.card').hide()" %>
produce the html
Fermer