This function returns an XMLHttpRequest() object after evaluating the browser’s capabilities. I’m sure there is a way to clean this up a bit as well, but it seems to work thus far. Suggestions are welcome.

    function createRequest() {
        try {
            var r = new XMLHttpRequest();
        } catch (trymicrosoft) {
            try {
                 r = new ActiveXObject("Msxml2.XMLHTTP");
            } catch (othermicrosoft) {
                try {
                    r = new ActiveXObject("Microsoft.XMLHTTP");
                } catch (failed) {
                    r = false;
                }
            }
        }
        return r;
    }