$user_postal=null;
    <form action='abc.com/list' id='locform' method='post'>
        <input type='hidden' id='latitude' name='latitude'>
        <input type='hidden' id='longitude' name='longitude'>
    </form>
    <script>
    var x = document.getElementById(\"latitude\");
    var y = document.getElementById(\"longitude\");
    var a;
    function getLocation()
    {
        if (navigator.geolocation)
        {
            navigator.geolocation.getCurrentPosition(showPosition);
        } else
        {
            x.innerHTML = \"Geolocation is not supported by this browser.\";
        }
    }

    function showPosition(position)
    {
        x.value = position.coords.latitude;
        y.value= position.coords.longitude;
        console.log(x);
    }
    function submitform()
    {
        document.forms[\"locform\"].submit();
        console.log(\"Value is sumitted\");
    }

    getLocation();
    </script>
$users_postal=$_GET['latitude'];
echo($users_postal);