pass parameter to popup window

I have a popup window that open cfm form(ical.cfm).

<SCRIPT language="JavaScript1.2">

function poponload()

{

testwindow= window.open ("ical.cfm", "mywindow",

    "location=1,status=1,scrollbars=1,width=300,height=300");

testwindow.moveTo(0,0);

}

</SCRIPT>

I need to pass evetID to the popup window. How I can do that. I need to pass (# CollegeEvents .eventID#)

<cfoutput query="CollegeEvents">

<img src="../images/events.jpg" onclick="poponload()"> 

</cfoutput>