How To Create A HttpHandler For Downloading Files From The Server

I created a HttpHandler for downloading files from the server. It seems it is not handling anything...I put a breakpoint in the ProcessRequest, it never goes there.

public class DownloadHandler : IHttpHandler
{
public void ProcessRequest(HttpContext context)
{
//download stuff and break point
}
}

It never stops there, as mentioned. I also registered it in the web.config.

<add verb="*" path="????" type="DownloadHandler" />

I am not sure about the path part of that entry. What do I have to enter there? I am downloading txt files, but the URL does not contain the filename, I somehow have to pass it to the handler. How would I do this? Session maybe?