$ document .ready function { $ is not defined 这个提示错误为什么
<script>
$(document).ready(function(){
$("#demoForm").validate(
{
rules:{
username:{
required:true,
minlength:2,
maxlength:10
},
password:{
required:true,
minlength:2,
maxlength:16
}
},
messages:{
username:{
required:"用户名必须填写",
minlength:"用户名最小为2位",
maxlength:"用户名最大为10位"
},
password:{
required:"必须填写密码",
minlength:"密码最小为2位",
maxlength:"密码最大为16位"
}
}
});
});
</script>
