[Plugin: Contact Form 7] Getting Previous URL

I would like users to send me Dead Link reports using Contact Form 7. So what I want is for the URL of the previous page the visitor was at to be included in the form.

Basically one page will have a “Report Dead Link” link and when the user clicks it, it will take them to the form. In that form I want the URL from where the user just came from to be included. How can this be done?

Thanks