BootstrapTema

<div class="modal fade bs-example-modal-lg" id="imagemodal" tabindex="-1" role="dialog" aria-labelledby="myLargeModalLabel"  
aria-hidden="true">  
    <div class="modal-dialog modal-lg" role="document">  
      <div class="modal-content">  
        <div class="modal-header">  
          <button type="button" class="close" data-dismiss="modal"  
aria-label="Close"><span  
aria-hidden="true">×</span></button>  
          <h4 class="modal-title" id="myModalLabel">Изображение в модальном окне</h4>  
        </div>                
        <div class="modal-body">  
          <img src="" class="imagepreview" style="width: 100%;" />  
        </div>  
      </div>  
    </div>  
  </div>  

  <script>  
  $(function() {  
     $('.item').on('click', function() {  
        $('.imagepreview').attr('src', $(this).find('img').attr('src'));  
        $('#imagemodal').modal('show');     
     });          
  });  
  </script>