ok so i have the code:

link(url);
{
var http="http://";
var start='index.html?fsrc="'
if (url.indexOf("www.")==0)
{
var furl=http.concat(url);
}
else
{
furl=url;
}
var ffurl=start.concat(furl);
return ffurl;
}

It's supposed to be used something like this:

<a href='link("www.google.com")'>Text</a>

The issue I keep having is that it does nothing. I've got no clue what I'm doing wrong.

The first thing its supposed to do is check if the first 4 characters of the url inserted in link() are "www.". If they are, it's supposed to put an "http://" in front of it. Then its supposed to combine it with 'index.html?fsrc="' to make something like: index.html?fsrc="http://www.google.com". Then its supposed to use that as the href for the link.

I'm not new to javascript, but I don't write my own functions too often, and i rarely ever manipulate strings like this. Also, I've never used a function in an "a" tag before.

Thanks in advance.

...
return ffurl;

not a surprise it does nothing, as it should be used by something else and be using the return to do something.

maybe something like

<a href='top.location=link("www.google.com");'>Text</a>

but this is plain dumb...
Search engines cannot follow a link like that.
Browsers with javascript disabled cannot follow them neither.

And furthermore, what for !?
Why follow a link whose URI have been generated via javascript?
I cannot see any good reason for it.

Though best practices recommend against it, what you want to do is:

<a href="javascript:link('www.google.com')">Text</a>