ASP Link Query...

I have the following link:

<A HREF=""Schedule.asp?JobNumber=" & RS("JobNumber") & "&PONumber=" &
RS("PONumber") & """>" & RS("JobNumber") ONCLICK= popup() & "</a>


I want the link to reference a function in the <Script> tag as
follows:

<script>

function popup() {
window.open( "Schedule.asp" , ""
,"top=40,left=40,width=200,height=100" ) ;
}

</script>

I am not sure where to place the ONCLICK code in the hyperlink as this
link is written out via response.write......Its all the " " & ' ' that
get me ...