Stopping A Unique For I=0 Loop At 5 Entries?

I've borrowed some code from various sources to get a delicious JSON feed onto my website. The problem is it this loop gives me the entire feed that is available, where I would only like to have 5 current entries. I understand how to do this in a for i=0 loop, however there is an extra bit of code that I do not understand within the loop. What do I need to do to end this loop at 5 entries instead of the 15 or so it generates?

Code:

<script>

<!--To be honest I have no idea what this does. I sampled code from 3 different resources to make this work, and the author of this code didn't attempt to explain what is going on here. It doesn't work without it. I'm fairly certain it parses the JSON file so that it is readable. -->

Function.prototype.bg = function(ms){
this.PID = setInterval(this,ms);
return this;

[code]...