อยากเปลี่ยนตัวแปร var javascript ที่หลังจากรับค่า แล้วมาเป็น php

<script src="jquery-1.11.2.min.js"></script>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<?php
$connect = mysqli_connect("localhost", "root", "1234", "ioonresort");
mysqli_set_charset($connect,"utf8");
$output = '';
if(isset($_POST["query"]))
{
$search = mysqli_real_escape_string($connect, $_POST["query"]);
$query = "
SELECT * FROM Device join devicetype using(DeviceTypeID) join unitcount using(UnitcountID)
WHERE DeviceName LIKE '%".$search."%' or   DeviceTypeName LIKE '%".$search."%'
or   UnitcountName LIKE '%".$search."%'
";
}
else
{
$query = "
SELECT * from device join devicetype using(DeviceTypeID) join unitcount using(UnitcountID)  order by DeviceID ASC ";
}
$result = mysqli_query($connect, $query);
if(mysqli_num_rows($result) > 0)
{
?>
<script language="javascript">
function chk( )
{
  var txtQty=document.getElementById('txtQty').value;
}
</script>
<?
echo "<center>";
echo "<h1><font>พนักงาน</font></h1>";
echo"<br>";
echo"<br>";
echo"<br>";

echo "<table border='1' width='50%'height ='50%'>";
echo "<tr>";
echo "<td align='center'><h3>&nbspรหัสอุปกรณ์&nbsp</td>";
echo "<td align='center'><h3>&nbspชื่ออุปกรณ์&nbsp</td>";
  echo "<td align='center'><h3>&nbspจำนวน&nbsp</td>";
echo "<td align='center'><h3>&nbspหน่วยนับ&nbsp</td>";
echo "<td align='center'><h3>&nbspจำนวนที่เบิก&nbsp</td>";
echo "<td align='center'><h3>&nbspเบิก&nbsp</td>";
echo "</tr>";
while($show = mysqli_fetch_array($result))
{

  echo "<tr>";
  echo "<td align='center'><h3>&nbsp".$show['DeviceID']."&nbsp</h3></td>";
  echo "<td align='center'><h3>&nbsp".$show['DeviceName']."&nbsp</h3></td>";
    echo "<td align='center'><h3>&nbsp".$show['total']."&nbsp</h3></td>";
    echo "<td align='center'><h3>&nbsp".$show['UnitcountName']."&nbsp</h3></td>";
  echo "<td align='center'><h2><input type='text' name='txtQty' id='txtQty' value='1' size='2'></h2></td>";
<?$txtQty?><script>document.write(txtQty)</script>

  ?>
  <td align="center"><a href='order.php?id=<?php echo $show['DeviceID'];?>&qty=<?echo $txtQty;?>'></h2> <input name="submit" type="submit" value="Submit"  class ="button" onclick="return chk()" /></td>


  <?

  echo "</tr>";
  }
  echo "</table>";

}
else
{
echo 'Data Not Found';
}
?>