Answer by Nabeel for Bootstrap modal appearing under background

Solution is to put modal directly under body tag. if that is not possible for some reason then just add overflow: visible property to tag enclosing the modal. or just use the following code:

<script>
    $(document).on('show.bs.modal', '.modal', function () {
        $('.div-wrapper-for-modal').css('overflow', 'visible');
    });

    $(document).on('hide.bs.modal', '.modal', function () {
        $('.div-wrapper-for-modal').css('overflow', 'auto');
    });
</script>
<div class="div-wrapper-for-modal">
    <div class="modal hide fade">
        <div class="modal-header">
            <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
            <h3>Modal header</h3>
        </div>
        <div class="modal-body">
            <p>One fine body…</p>
        </div>
        <div class="modal-footer">
            <a href="#" class="btn">Close</a>
            <a href="#" class="btn btn-primary">Save changes</a>
        </div>
    </div>
</div>