Submit The Form Data To The Popup Window Without A Submit Button

The following will submit the form data to popup by clicking the submit button. I want it will submit the form automatically to the popup, there is no submit button in this page. Basically this page should not show up.

<script type="text/javascript">
function submitmyform(f) {
f.target = 'foo'
window.open('',f.target,'menubar=no,scrollbars=no, width=800,height=800');
f.submit();
return false;
}
</script>

<form name="myform" action="popup.asp" target="_blank" method="post"
onsubmit="return submitmyform(this);">
<input type="hidden" name="item" value="item"/>
<input type="submit" value="submit to popup"/>
</form>