Email validation in jquery

Email validation in jquery

HTML

<link rel="stylesheet" href="http://getbootstrap.com/dist/css/bootstrap.min.css">
<script src="http://getbootstrap.com/dist/js/bootstrap.min.js"></script>
<div>
<input type="text" id="email" class="form-control">
</div>
<button type="button" class="btn btn-success" id="submit">Submit</button>

JavaScript

$(document).on("click", "#submit", function (e) {
    e.preventDefault();
    var pattern = new RegExp(/^[+a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{1,6}$/i);
    var emailAddress = $("#email").val();

    if ($("#email").val() == "") {
        $("#email").parent().addClass('has-error').removeClass('has-success');
    } else if (!pattern.test(emailAddress)) {

        $("#email").parent().addClass('has-error').removeClass('has-success');
    } else if ($("#emailExistance").val() == "0") {
        $("#email").parent().addClass('has-error').removeClass('has-success');
    }
    else{
        
    }
});