Jquery validate example
HTML
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.13.1/jquery.validate.min.js"></script>
<form id="form1">
<label for="name">First Name</label>
<input type="text" name="name" />
<input type="button" id="btn" value="ok" />
</form>
CSS
#form1 label.error {
color: #FB3A3A;
display: block;
margin: 10px;
padding: 0;
text-align: left;
}
JavaScript
$(document).ready(function (){
$("#form1").validate({
rules: {
name: "required"
},
messages: {
name: "Please specify your name"
}
});
$('#btn').click(function() {
$("#form1").valid();
});
});