in a ok project，it should like this:
<script type="text/javascript">jQuery(document).ready(function () {
jQuery('#form-signup').yiiActiveForm({"username":{"validate":function (attribute, value, messages) {yii.validation.required(value, messages, {"message":"Username\u4e0d\u80fd\u4e3a\u7a7a\u3002"});yii.validation.string(value, messages, {"message":"Username\u5fc5\u987b\u662f\u4e00\u6761\u5b57\u7b26\u4e32\u3002","min":2,"tooShort":"Username\u5e94\u8be5\u5305\u542b\u81f3\u5c112\u4e2a\u5b57\u7b26\u3002","max":255,"tooLong":"Username\u53ea\u80fd\u5305\u542b\u81f3\u591a255\u4e2a\u5b57\u7b26\u3002","skipOnEmpty":1});},"id":"signupform-username","name":"username","validateOnChange":true,"validateOnType":false,"validationDelay":200,"container":".field-signupform-username","input":"#signupform-username","error":".help-block"},</script>
but in my project,when i enter email or username that is invalid,no hints or error shows! when i check the code generated by yii,i see null args of yiiActiveForm~
<script type="text/javascript">jQuery(document).ready(function () {
jQuery('#form-signup').yiiActiveForm([], []);
});</script>
who can tell me why?