How to prevent Internet Explorer from downloading JSON response?

How to prevent Internet Explorer from downloading JSON response?

I have a feeling that the solution to my problem is stupidly simple, but crawling through Google has provided me with none.

I'm trying to handle the login process on one of my clients' site using the AJAX functionality provided by jQuery.

Here is the $.ajax() call in question:

        
    
         
  1.  $.ajax({
    2. 
         
  2.         "cache": false,
    3. 
         
  3.         "complete": function()
    4. 
         
  4.         {
    5. 
         
  5.             $('#spinner').hide();
    6. 
         
  6.         },
    7. 
         
  7.         "data": { "user": user,
    8. 
         
  8.                   "pass": pass
    9. 
         
  9.                 },
    10. 
         
  10.         "dataType": "json",
    11. 
         
  11.         "error": function(){},
    12. 
         
  12.         "success": function(data, text)
    13. 
         
  13.         {
    14. 
         
  14.             if (data.id == 0)
    15. 
         
  15.             {
    16. 
         
  16.                 msgbox('Incorrect input', '<p>The username or password is incorrect.</p>');
    17. 
         
  17.             }
    18. 
         
  18.             else
    19. 
         
  19.             {
    20. 
         
  20.                 window.location = base_url + 'admin';
    21. 
         
  21.             }
    22. 
         
  22.         },
    23. 
         
  23.         "type": "POST",
    24. 
         
  24.         "url": base_url + "admin/login"
    25. 
         
  25.     });
    26.


This works fine in Firefox, but Internet Explorer pops up a dialog asking me where to save the JSON response as a file.

Here is an example of the JSON that the server returns on valid login:

              
    
               
  1.  {
    2. 
               
  2.     "id": 1234,
    3. 
               
  3.     "name": "SomeUser",
    4. 
               
  4.     "email": "some@address.com",
    5. 
               
  5.     "lastlogin": "2010-01-13 10:57:18"
    6. 
               
  6. }
    7.

I have already set the Content-Type header of the response to application/json, which made no difference. I also tried text/html and text/plain, but in these cases Internet Explorer shows the JSON as HTML or plain text in the browser window... *sigh*

Googling also gave me the suggestion to just use text/plain and eval() the response myself, but I remember reading elsewhere that this is pretty unsafe. I am unsure on the specifics on this, though.

Dear jQuery gods, can you help me out? ;)