* sets up the object with the AJAX url and security nonce, also retrieves language properties
 */
setup: function(url, nonce, pluginUrl, userId, callbackFn, skipLoadGlobals) {
    if(!PI.ajaxSetup) {
        // create custom widgets
        initPICustom();

        PI.globals.pluginUrl = pluginUrl;
        PI.userId = userId;
        this.url = url;
        this.nonce = nonce;

        if(!skipLoadGlobals) {
            this.loadGlobalData(callbackFn);
        }
        else {
            callbackFn();
        }
    }
    else {
        alert('Ajax setup function already called');
    }
},

getUserOldestResultYear: function(userId, callbackFn) {
    jQuery.ajax({
        type: "post",
        url: PI.Ajax.url