get the parent url of iframe in PHP

Question

I am creating a widget that would load in a IFrame and users will be able to place the widget on their own website. How would I get the URL of the website that is using the

Answer 1

I have also tried to echo "$_Server[referrer]" in the IFrame page and that did return the IFrame parent URL, but how easy is it for someone to manipulate the referrer variable?

Pretty easy, but so is disabling JavaScript! However, if a web site uses your