Set the value of this menu and fires the 'update' event.
@param {Object} data The data to assign to this menu
function (data) {
        var me = this,
            fields = me.fields,
            key,
            field;

        for (key in fields) {
            if (fields.hasOwnProperty(key)) {
                // Prevent field's change event from tiggering a Store filter. The final upate event will do that
                field =fields[key];
                field.suspendEvents();
                field.setValue(key in data ? data[key] : '');
                field.resumeEvents();
            }
        }

        // Trigger the filering of the Store
        me.fireEvent('update', me);
    }