import Qt 4.7

QtObject {

    id: obj

    property string url

    property string which

    property bool threw: false

    onWhichChanged: {

        var x = new XMLHttpRequest;

        x.onreadystatechange = function() {

            if (x.readyState == which) {

                obj.threw = true

                throw(new Error("Exception from Callback"))

            }

        }

        x.open("GET", url);

        x.setRequestHeader("Test-header", "TestValue");

        x.send();

    }

}