SO - 20581731

HTML

<script src="http://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.11.1/jquery.validate.js"></script>
<script src="http://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.11.1/additional-methods.js"></script>
<form id="myform" action="#">
    <input type="file" name="resume" />
    <br/>
    <input type="submit" value="Submit" />
</form>

JavaScript

$(document).ready(function () {
    
    $('#myform').validate({
        rules: {
            resume: {
                required: true,
                extension: "docx|rtf|doc|pdf"
            }
        },
        messages: {
            resume: {
                required: "Please upload resume",
                extension: "Please upload valid file formats"
            }
        }
    });
    
});