получить значение из сеанса в java script на php

---

Привет,
Друзья у меня есть код

<?php <br mode="hold" /?>session_start();

if( isset($_POST['Submit'])) {
   if( $_SESSION['security_code'] == $_POST['security_code'] && !empty($_SESSION['security_code'] ) ) {
		// Insert you code for processing the form here, e.g emailing the submission, entering it into a database. 
		//echo 'Thank you. Your message said "'.$_POST['message'].'"';
		echo "<script>alert('Thank you. Your message said.....')</script>";
		echo "<script type='text/javascript'>
    alert('".json_encode($_SESSION['security_code'])."');
</script>";
		unset($_SESSION['security_code']);
   } else {
		// Insert your code for showing an error message here
		echo 'Sorry, you have provided an invalid security code';
		echo "<script>alert('Sorry, you have provided an invalid security code')</script>";
   }
} else {
?>
<tr>
                        <td height="50" valign="top"> </td>
                        <td valign="top"><img src="CaptchaSecurityImages.php?width=100&height=40&characters=5" /></td>
                      </tr>
<tr>
                        <td height="30" valign="top">Security Code:<span class="required" style="color:#93B928;">*</span></td>
                        <td valign="top"><input id="security_code" name="security_code" type="text" style="width:100px;"/></td>
                      </tr>
                       <tr>
                        <td height="50" valign="top"> </td>
                        <td valign="top"><input class="button" name="Submit" value="Send" type="submit" /></td>
                      </tr>
    	}
?>

мне нужно это значение сеанса в моем коде java script

function form_validation()
{
hh=document.WebToLeadForm;
if(!hh.security_code.value==""){
var a = <?php echo $_SESSION['security_code']; ??>
alert("Please wait to check for match");
return false;
}

я использую код, но не работает может u pls выяснить, как его использовать..

заранее спасибо

Раджеш

---