In Wordpress, I try to write o cookie into a hidden field. I have a cookie:
   if(isset($_GET['ecselis']))
     {
     $cookie_name = "ecselis";
     $cookie_value = $_GET['ecselis'];
     setcookie($cookie_name, $cookie_value, time() + (86400 * 30),   "/");
     $_SESSION["ecselis"] = $cookie_value;
     }
   else if(isset($_COOKIE['ecselis'])) {
      $_SESSION["ecselis"] = $_COOKIE['ecselis'];
     }
   else
     {
     }
This working fine. But I dont realy know how should I write it into a hidden field
<input id="ecselis_field" name="ecselis_field" type="hidden" value="" />
I tried
<input id="ecselis_field" name="ecselis_field" type="hidden" value="$.cookie('ecselis')" />
but it doesn't work at all.
 
    