enot wrote in php

Passing variables from JS to PHP

Hi -- I ran into problem passing variables from Javascript to PHP server side.
Below is the relevant fragment of the code

< form name="Form1" action=< "?php echo $PHP_SELF ?" > method="post" >
< input type="hidden" name="latctr" />
...
</form>

JS:
var center = map.getCenterLatLng(); ---- Google Maps API ----
document.Form1.latctr.value = center.y;
alert (document.Form1.latctr.value); ---- displays the value all right ----
PHP:
$latctr = $_POST['document.Form1.latctr.value'];
-- or --
$latctr = $_POST['latctr'];

neither one works ($latctr is blank).

Any hints or relevant links are appreciated. I tried to search google groups and some other forums and I don't see what I'm doing different compared to suggested solution with hidden variables and _POST method.