如何在Jquery验证插件中使用ajaxUserCall函数

<input id="user" name="user" type="text" class="validate[required,ajax[ajaxUserCall]]" />

在validationEngine js文件中:

"ajaxUserCall": {
    "url": "ajaxValidateFieldUser",
    "extraData": "name=eric",
    "extraDataDynamic": ['#user_id', '#user_email'],
    "alertText": "* This user is already taken",
    "alertTextOk": "All good!",
    "alertTextLoad": "* Validating, please wait"
},

• url-要调用的远程restful服务
• extraData-要发送的可选参数
• extraDataDynamic-可选的DOM id,其值应作为参数发送
• alertText-验证失败时的错误提示消息
• alertTextOk-验证成功时的可选提示(显示绿色)
• alertTextLoad-执行验证时显示的消息