[Kristoffer G]

ja alltså det va väl det du menade innan?

function getquerystring() {
var word = document.getElementById("feed").value
qstr = 'feed=' + escape(word);
return qstr;
}


<form name="feeds" action="index.html" method="POST">
<select id="feed">
<option value="">Välj</option>
<option value="http://www.geiser.se/feed" onClick='xmlhttpPost("show_feed.php")'>Geiser.se</option>
<option value="http://feeds.feedburner.com/tkjblogg?format=xml" onClick='xmlhttpPost("show_feed.php")'>TkJ</option>
<option value="http://www.dan.se/feed" onClick='xmlhttpPost("show_feed.php")'>Dan.se</option>
</select>