javascript document referrer

Returns a string of the URL of the page from which the current page was accessed, provided the original page had a link to the current page. Many server logs capture this information as well. Scripts can see whether the visitor reached the current document from specific origins and perhaps present slightly different content on the page accordingly. If the visitor arrived by another method, such as typing the document URL into a browser dialog or by selecting a bookmark, the referrer property returns an empty string. Many versions of IE for Windows fail to report the correct referrer URL, often showing the URL of the current page instead.