How do I randomize two links on one page?

i'm trying to have two links on one page that each have a different set of variable urls. i can only get one of the links to work my code looks like this:

<script type="text/javascript">
var url=[
'bear52.html',
'bear53.html'
]; 
window.onload=function()
{document.getElementById('trig').onclick=function(){
location.href=url[Math.floor(Math.random()*url.length)];}}
</script>
<a href="#" id="trig">
YOU OKAY?</a>


<BR><script type="text/javascript">
var url=[
'bear30a.html',
'bear31a.html'
]; 
window.onload=function()
{document.getElementById('trig').onclick=function(){
location.href=url[Math.floor(Math.random()*url.length)];}}
</script>
<a href="#" id="trig">
RUN AWAY</a>

any help?