jQuery "Cannot read property 'defaultView' of undefined" error

I am using jQuery to post a form field to a PHP file that simply returns 1/0 depending on whether it worked or not...

Extract of the code:

$.ajax({
    url: "ajax/save_text.php", //Relative?!?
    //PHP Script
    type: "POST",
    //Use post
    data: 'test=' + $(this).val(),
    datatype: 'text',
    //Pass value       
    cache: false开发者_运维问答,
    //Do not cache the page
    success: function(html) {
        if (html == 1) {
            $(this).hide().siblings('span').html($(this).value).show();
                    alert("awesome!");
        } else alert('It didn\'t work!');
    },
    //Error
    error: function() {
        alert("Another type of error");
    }
});

However everytime it is successful (html == 1) the console throws up the error

Uncaught TypeError: Cannot read property 'defaultView' of undefined"

and the alert never happens...?

Google doesn't seem to have much info on this error and jQuery, who knows the cause?

It's because this isn't what you were dealing with before, it's now tha ajax jQuery object, add the context option of $.ajax() like this:

$.ajax({
  context: this,
  url: "ajax/save_text.php",
  ...

This way this inside your callbacks refers to the same this as when you're calling $.ajax(). Alternatively, just hold onto a reference to this in a separate variable.

Also, you'll need to adjust $(this).value, you probably meant this.value or $(this).val().