How to make my random string end in .html (rephrased)

Hello peoples.

You may of been my question before, regarding the same issue. I, however, cannot seem to make my string end in .html. Here's the code:

$file = md5( time().'' );

This does create a random sting, which I am using to generate links, like so: mywebsite.com/ffwjiafqoapwdlc. But I want it to end in .html: mywebsite.com/ffwjiafqoapwdlc.html. Is there anything I can do to get this result?

 - Thanks, Xanco