Jquery – Microsoft JScript runtime error: Unable to set value of the property ‘control’: object is null or undefined

For the record, as far as I can tell, you had two problems:

1. You weren't passing a "jsonp" type specifier to your $.get, so it was using an ordinary XMLHttpRequest. However, your browser supported CORS (Cross-Origin Resource Sharing) to allow cross-domain XMLHttpRequest if the server OKed it. That's where the Access-Control-Allow-Origin header came in.

2. I believe you mentioned you were running it from a file:// URL. There are two ways for CORS headers to signal that a cross-domain XHR is OK. One is to send Access-Control-Allow-Origin: * (which, if you were reaching Flickr via $.get, they must have been doing) while the other was to echo back the contents of the Origin header. However, file:// URLs produce a null Origin which can't be authorized via echo-back.

The first was solved in a roundabout way by Darin's suggestion to use $.getJSON. It does a little magic to change the request type from its default of "json" to "jsonp" if it sees the substring callback=? in the URL.

That solved the second by no longer trying to perform a CORS request from a file:// URL.

To clarify for other people, here are the simple troubleshooting instructions:

1. If you're trying to use JSONP, make sure one of the following is the case:
   • You're using $.get and set dataType to jsonp.
   • You're using $.getJSON and included callback=? in the URL.
2. If you're trying to do a cross-domain XMLHttpRequest via CORS...
   1. Make sure you're testing via http://. Scripts running via file:// have limited support for CORS.
   2. Make sure the browser actually supports CORS. (Opera and Internet Explorer are late to the party)

The error is caused by your $(this) not referring to anything, or the window object rather. It depends on how your function is called. It's best to pass the element you want to use into the function deleteConfirmation() like so:

$("#deleteAnswer").bind("click", function() {
    deleteConfirmation(this);
});

function deleteConfirmation(element) {
    jAlert('Deleted succsfully', 'Deletion Confirmation', function() {
        alert("The user clicked ok");

        // Hides the element that caused the click event
        $(element).fadeOut('slow', function () { $(element).remove(); });
    });
}

See this jsfiddle for an example.

If you're trying to fadeOut the alert box itself, that is done by default, as you might already know.