Con el siguiente codigo puedes hacer que se abra una ventana emergente en tu web.

<script LANGUAGE="JavaScript">
<!--
function launch(newURL, newName, newFeatures, orgName) {
var remote = open(newURL, newName, newFeatures);
if (remote.opener == null)
remote.opener = window;
remote.opener.name = orgName;
return remote;
}
function launchRemote() {
myRemote = launch("http://www.skyandstars.net", "myRemote", "height=400,width=110,channelmode=0,dependent=0,directories=1,fullscreen=0,
location=1,menubar=0,resizable=0,
scrollbars=0,status=0,toolbar=0", "myWindow");
}
// -->
</script>