array datepicker

array datepicker

hello

i want show datepicker in my array. here my code. i can click on 1st box & show the date. but when i click on 2nd box nothing happen.

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>

<link rel="stylesheet" href="../apps/css/jquery-ui.css">
<script src="../apps/js/jquery-1.12.4.js"></script>
<script src="../apps/js/jquery-ui.js"></script>

<script>
  $( function() {
    $( "#datepicker" ).datepicker();
  } );
</script>


</head>

<body>
<form method="post" name="form1" >
    <input type='text' name='date_st[0]' id="datepicker" value='' /><br />
    <input type='text' name='date_st[1]' id="datepicker" value='' />
</form>
</body>
</html>