pop-up window java

how will i identify if the window im in is a pop up window?
i have this code i got on the net

<SCRIPT LANGUAGE=”JavaScript”>
function popUp(URL) {
day = new Date();
id = day.getTime();
alert (“”+id+””);
eval(“page” + id + ” = window.open(URL, ‘” + id + “‘, ‘toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=0,width=1024,height=768,left = 0,top = 0’);”);
<%
if request(“Submit”)=”” then
else
‘response.Redirect “selfcloser.asp”
end if
%>
}
</script>

Or how can i programmatically identify if the window property is statusbar=0, menubar=0, resizable=0. so it wont pop-up other window when its already a pop-up when clicking a button.
Thanks..

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