There's a few different ways people create links to javascript function, after some looking around here's what seems to be the better ways:

CODE
<a href="java script:{}" onclick="foo()">Call it</a>
<a href="java script:;" onclick="foo()">Call it</a>
<a href="java script:void(0);" onclick="foo()">Call it</a>

<a href="#" onclick="foo(); return false">Call it</a>


And many people will say to back it up with a server-side page or needs-JS page like:

CODE
<a href="jsrequired.html" onclick="foo(); return false">Call it</a>