WIERD problem

WIERD problem

Does anyone know the solution to this seemingly simple problem?
This works fine below:

$.ajax({
   type: "GET",
   url: "review_vote.php",
   data: "review_id=55&feedback=1",
   success: function(data) {
      alert("finished");
   }
});


BUT! once I put review_vote.php in a subdirectory called ajax, the file cannot be loaded...

$.ajax({
...
url: "ajax/review_vote.php"
...


Anyone know what's going on here? Only thing I can think of is perhaps the forward slash character needs to be escaped, but I tried various combinations and that doesn't help...

Thanks in advance.