jQuery Date Picker Input Date Format

HTML

<link rel="stylesheet" href="http://code.jquery.com/ui/1.8.21/themes/base/jquery-ui.css">
<input type="radio" class="radio1" name="radio1" value="radio1" checked> Radio 1 

      <input type="radio" class="radio1" name="radio1" value="radio2" >Radio 2<input 
             type="text" 
             id="mydatepicker" 
             aria-controls="sample_1" 
             class="form-control input-small input-inline" >

JavaScript

$(function() {   

       $(".radio1").change(function () {    
        if($(".radio1:checked").val()=="radio2"){
          $('#mydatepicker').datepicker('destroy');
            $('#mydatepicker').datepicker({
              format: 'dd/mm/yyyy',        
              minDate: '11/23/2015'
            });
        }else{
          $('#mydatepicker').datepicker('destroy');
          $('#mydatepicker').datepicker({
              format: 'dd/mm/yyyy',                  
            });      
       }
      });
      $('#mydatepicker').datepicker({
              format: 'dd/mm/yyyy',                  
            }); 
      });