[jQuery] $.get ajax method callback being called before the script return...

[Jonny]

I'm far from a specialist , but i think its a piece of cake so , here
we go...

I have the following function being called whenever a combobox is
changed:

function ajax_do(pAcao, pId , pIdt){
  if (typeof pId == 'undefined' ) pId = '0';
  if (typeof pIdt == 'undefined' ) pIdt = '0';
  $('#messagemLoading').show();
  $.get("carrinho.php", { acao: pAcao, id: pId , idt : pIdt },
  function(data){
        $('#messagemLoading').hide();
    return data;
  });
}

it's working , but i need tomake sure the request is finished before
allowing the user to continue, the #messagemLoading  should do the
job, in Firefox it's working fine and the #messagemLoading only hides
when the request ends, but in internet explorer the #messagemLoading
pops and close before the request is finished =/