А при таком варианте
tmp.html
<!DOCTYPE html>
<html>
<head>
<!--
<script src='http://code.jquery.com/jquery-latest.js'></script>
<link rel='stylesheet type=text/css href=tmp.css' />
-->
<style type='text/css'>
</style>
<script type='text/javascript'>
function test(){
var val='Ok';
window.open('tmp1.html?prm='+val);
};
</script>
</head>
<body>
<button onclick='test();'>Test</button>
</body>
</html>
tmp1.html
<!DOCTYPE html>
<html>
<head>
<!--
<script src='http://code.jquery.com/jquery-latest.js'></script>
<link rel='stylesheet type=text/css href=tmp.css' />
-->
<style type='text/css'>
</style>
<script type='text/javascript'>
var val=window.location.search.match(/prm=([^,$]*)/)[1];
alert(val);
</script>
</head>
<body>
<p>Test</p>
</body>
</html>
Уже работает...