SO - 24545605

HTML

<script src="http://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.12.0/jquery.validate.js"></script>
<form id="myform">
    <input name="mobile" type="text" />
    <input type="submit" />
</form>

JavaScript

$(document).ready(function() {

    $('#myform').validate({
        rules: {
            mobile: {
                required: true
            }
        },
        messages: {
            mobile: {
                required: 'Enter Mobile No.'
            }
        }
    });
    
});