Problem with window alert

Hi guys, i want to appear a new window in web browser application with a messege. i try with echo but it can't. as same as the window alert. the code is following

PHP Code:

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<?php
session_start();
if ((!(isset($_SESSION['usertype'])))||($_SESSION['usertype']!="admintp")){
header( 'Location: ../index.php');
}
$id = $_POST['id'];
include 'catalogdbinfo.php';
//if he is captain then don't delete
$specs=mysql_query("select speciality from tblemployee where id=".$id);  
$captain=mysql_query("select empid from tblroute where empid=".$id);  
if((mysql_result($specs,0,'speciality')=="Captain") && (mysql_numrows($captain)>0))
[U]echo "the employer is captain and he can not delete";[/U]

else
{
//else delete
mysql_query("delete from tblemployee where id=".$id);
 [U]echo "  the employer delete";[/U]
 }
mysql_close($link);
?>
 
    <script language="javascript">
    window.location="updateemp.php";
    </script>

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