Javascript Cookie Help

[BlackRaven]

I want the script to do the following

1) Get postid through voting function
2) Check to see if the cookie voteids exists
3) If not create cookie voteids with a value of postid with a underscore char
4) if cookie does exit add postid with underscore after the current cookie value

function voting(postid)
{

if (document.cookie.length > 0)
{
var begin = document.cookie.indexOf(voteids+"=");
if ( begin!= -1)
{
begin += voteids.length+1;
var end = document.cookie.indexOf(";", begin);
if (end == -1)
{
end = document.cookie.length;
}
var ids=document.cookie.substring(begin, end);
ids +=postid+"_";
document.cookie = "voteids="+ids+"_";
}
else
{
document.cookie = "voteids="+ids+"_";
}

}
else
{
document.cookie = "voteids="+ids+"_";
}

}

[Logician]

This should do the job, and ignore duplicates:

function voting(postid) 
{ 
 var cv, dup=false; 
  
 if(document.cookie && (cv=document.cookie.match(/voteids=([^;]+);*/i)) )  
  if(cv[1].match(new RegExp('_?'+postid+'([_;]¦$)'))) 
   dup=true; 
 if(!dup)  
  document.cookie='voteids='+(cv?cv[1]+'_'+postid:postid); 
}