debugging a dll

Hi, I have a question.

I have a web project that I have built a dll for. So in my solution I have
two projects, 1-website and 2-my Dll. When I do a build it builds both fine.
I even have my dll set up so when it builds the resulting dll lands in my
bin directory for my website. So all that is great. What I am wondering is
if there was a way to set it up so when I run in debug, it uses my dll code
instead of the compiled dll. So that way I can step through my dll code
while I am trying to call it. I hope this makes since. Please let me know
if I can make any of this more clear.

Thanks,
Michael