can any1 tell me whats wrong with my code.i cannot edit my data

$sql=caseQuery("select dt from update_dt where dt_id=1");
<div style="position:absolute; top: 250px; left: 500px; width: 4639px; height: 109px;"> 
  <fieldset style="width:20px">
<legend ><b><NOBR>Edit Date</NOBR></b></legend>
<form name="frm"  action="location.php" method="post" >
	<table width="250" border="0">
    <td><input name="sdate" id="sdate" type="text" size="15" VALUE="<?php echo $dt; ?>"readonly="readonly" />
  <img src="../images/cal.gif" id="srcDOFImg">
  <link type="text/css" rel="stylesheet" href="../inc/jscalender/css/jscal2.css" />
  <link type="text/css" rel="stylesheet" href="../inc/jscalender/css/border-radius.css" />
  <link id="skin-win2k" title="Win 2K" type="text/css" rel="alternate stylesheet" href="../inc/jscalender/css/win2k/win2k.css" />
  <link id="skinhelper-compact" type="text/css" rel="alternate stylesheet" href="../inc/jscalender/css/reduce-spacing.css" />
  <script src="../inc/jscalender/js/jscal2.js"></script>
  <script src="../inc/jscalender/js/lang/en.js"></script>      
			<script type="text/javascript">
          new Calendar({
                  inputField: "sdate",
                  dateFormat: "%d-%m-%Y",
                  trigger: "srcDOFImg",
                  bottomBar: true,
                  //max:  Calendar.dateToInt(new Date()),
                  onSelect: function() {
                          var date = Calendar.intToDate(this.selection.get());
<input type="button" name= "edit" value="Edit" onclick="return checkform();" />
 if (isset($_POST["edit"]))
$dt = escape($_POST['sdate']);
echo "$dt";
$sq=caseQuery("update update_dt set dt='$dt' where dt_id=1");
	  echo "cannot Edit Date";

You should pass date in yyyy-mm-dd format to mysql server