document.referrer code example
Example: javascript get referrer
// website2.html
<img src="website3.com/pxl.gif" id="pxl" />
<script>
document.getElementById('pxl').src += '?ref=' + encodeURIComponent(document.referrer);
</script>
// website2.html
<img src="website3.com/pxl.gif" id="pxl" />
<script>
document.getElementById('pxl').src += '?ref=' + encodeURIComponent(document.referrer);
</script>