jQuery.extend({
    postJSON: function(url, data, callback)
    {
        return this.post(url, data, callback, "json");
    },
    postJSONWS: function(url, data, callback)
    {
        var _data = "{}";
        if (typeof data == "function" && callback == null)
        {
            callback = data;
        }
        if (data != null && typeof data != "function")
        {
            _data = data;
        }
        return this.ajax({ contentType: "application/json", type: "POST", url: url, data: _data, dataType: "json", success: callback });
    },
    getXML: function(url, data, callback)
    {
        this.ajax({ type: "GET", url: url, dataType: "xml", data: data, success: callback });
    },
    postXML: function(url, data, callback)
    {
        this.ajax({ type: "POST", url: url, dataType: "xml", data: data, success: callback });
    }
});