I want to add Java confirm to the beginning of this formula, but I am not sure how

I have this formula:

If(Contains([Payment Status],"Not Paid")=false,"https://qb.com/db/bnjabvum6?a=dbpage&pageID=20";,
If([Payment Approved?]=true,"https://.qb.com/db/bnjabvum6?a=dbpage&pageID=15";,
If([PO#]="","https://qbp.com/db/bnjabvum6?a=dbpage&pageID=11";,

var text URL = URLRoot() & "db/"
& "bnjabvupd"
& "?act=API_EditRecord&usertoken=b3h8mh_k_c9j3i6gcvnzat8caff9m2quiq2m&rid=" & ToText([Record ID#])& "&_fid_364=1&_fid_365=" & URLEncode(User()) & "&_fid_483=" & URLEncode(Now());

"javascript:" &
"$.get('" &
$URL &
"',function(){" &
"location.reload(true);" &
"});" & "void(0);")))


I want to prepend this:

"javascript:confirm ('Are you sure you want to receive this line? ')"


Any ideas?

Thanks!