Some little trick to stop form submission
<form id="FORM_ID" class="purchaseForm">
<button type="submit" form="FORM_ID" value="Submit">Submit</button>
</form>
$('.purchaseForm').on('submit', function (e) {
e.preventDefault();
e.stopPropagation(); // Key shit !
console.log(e.currentTarget[0].value); // value of first form field
});