Anybody know???

[Havent_a_clue]

I'm currently working on a project and came across this piece of code. Unfortunately, as my user name suggests, i don't know whats going on. Could anybody help???
thanks in advance...

function flip(pic, r)
{
if(r == 2)
{
source = eval(pic + "2.src");
document[pic].src = source;
}
if(r == 1)
{
source = eval(pic + "1.src");
document[pic].src = source;
}
}

function link()
{
}

[redhead]

It's typicaly used in creating the change of pictures, when your mouse passes over a picture, and it is usualy called like:

onMouseOver="flip(this, 2); return true;"
onMouseOut="flip(this, 1); return true;"