Mouseover follower window


I’m making a kind of calendar on the website of my union.
I want it to have a picture in the dates that we have something planned.
That’s the very easy part; but I also want to have a mouseover effect : when I go over the picture I want there to apear a box with info and a picture; and I want it to follow my mouse when I’m still on the object (the first picture).

So does anybody know how I should do this last part? I know how to make a box appear; but I don’t know how to let it follow my mouse.

kind regards;

Anneleen ! x