PHP and Javascript Combined

Hi,

I'm working on a Javascript to update 2 listboxes with values, here's where PHP come in. I use PHP to get the values from a Database, but how can I use Javascript variables in PHP code?
What I'm trying to do looks something like this simplified:

<SCRIPT LANGUAGE="Javascript">
function getPerioder(selection)
{
var ftgID = selection.options[selection.selectedIndex].value;
<?php $result2=mysql_query("SELECT * FROM FtgPerioder WHERE ftgID=ftgID");
$object=mysql_fetch_object($result2);
$name=$object->name;
?>
document.form1.perioder.options[0].text=name;
}
</SCRIPT>


The thing I want to do is:
replace ftgID in
mysql_query("SELECT * FROM FtgPerioder WHERE ID=ftgID");
with the javascript variable

Help Greatly needed!
Many Thanks!
Jonas Versén

Since PHP is a server-side, it has already done it´s work when the html page is up (Javascript is client-side). So what you have to do is to run the script again with the new value.

//N.B