Edit in JSFiddle

<div id="myBtn" class="btn btn-primary" data-toggle="modal" data-target="#myModal">
  Contact us
</div>

<!-- Modal -->
<div id="myModal" class="modal hide fade">
  <div class="modal-dialog" role="document">
    <div class="modal-content">
      <div class="modal-header">
        <h5 class="modal-title">Contact us</h5>
        <button type="button" class="close" data-dismiss="modal" aria-label="Close">
          <span aria-hidden="true">&times;</span>
        </button>
      </div>
      <div class="modal-body">
        <!-- Empty -->
      </div>
    </div>
  </div>
</div>

<!-- Modal -->
<!-- <div id="myModal" class="modal hide fade">
  <div class="modal-header">
    <button type="button" class="close" data-dismiss="modal">×</button>
    <h3>Contact us</h3>
  </div>
  <div class="modal-body"></div>
</div>
 -->
<!-- Anymod -->
<script id="Anymod-script">
  (function (m,o,d,u,l,a,r,i,z,e) {
    u[m]={Project:o,rq:[],Opts:r,ready:function(j){u[m].rq.push(j)}};function j(s){return encodeURIComponent(btoa(s))};z=l.getElementById(m+'-'+a);r=u.location;
    e=[d+'/page/'+o+'/'+j(r.pathname)+'/'+j(r.host)+'?t='+Date.now(),d];e.map(function(w){i=l.createElement(a);i.defer=1;i.src=w;z.parentNode.insertBefore(i,z);});
  })('Anymod','8PP6M2','https://cdn.anymod.com/v2',window,document,'script',{});
</script>
<!-- /Anymod -->
$(document).ready(function () {
  $('#myModal').on('show.bs.modal', function (event) {
    var modal = $(this)
    modal
      .find('.modal-body')
      .html('<div id="anymod-mklod"></div>')
    Anymod.render()
  })
})