Why does my toilet run???????

I know some of you hate these kind of forums............but, I need to know.

I am sure there is someone who knows the answer.

After I flush my toilet it will run water for about a minute or so and then stop. I hate it b/c it never used to do that. We recently replace the handle, in the summer, and I think that is when it started. Any ideas on why the waters runs for so long?!?!?!?! Please!! Thanks