url
A string that specifies the URL of the new document that is to replace the current one.
The replace( ) method of the Location object loads and displays a new document. Loading a document in this way is different from simply setting location or location.href in one important respect: the replace( ) method does not generate a new entry in the History object. When you use replace( ), the new URL overwrites the current entry in the History object. After calling replace( ), the browser's
Back button does not return you to the previous URL; it returns you to the URL before that one.
When you are working with multiple frames and/or JavaScript-generated documents, you sometimes end up with quite a few temporary documents. If there are more than just a few of these documents, backing out of your web site with the
Back button can be annoying. If you use the replace( ) method to load these documents, however, you can prevent this problem.