[mothered]

This one is a little bit smaller and only relies on GetElementByID to do the trick.

I was actually curious and checked It out.

Code:

verify = function() {
var select = document.getElementById('select').value;
var site_id = document.getElementById('site_id').value;
if(site_id == "") {alert('Type a site to report!'); return false;}
if(select == "1") {window.open('https://feedback.smartscreen.microsoft.com/feedback.aspx?t=0&result=none&url='+site_id+'');}
if(select == "2") {window.open('https://safebrowsing.google.com/safebrowsing/report_phish/?url='+site_id+'');}
if(select == "3") {window.open('https://safebrowsing.google.com/safebrowsing/report_error/?url='+site_id+'');}
if(select == "4") {window.open('https://safebrowsing.google.com/safebrowsing/report_badware/?url='+site_id+'');}
}

Good work.