Plugin Coding Question: Function Syntax

[ThePimp]

What is the proper syntax for calling a function in a plugin?

Here's my issue, I'm including a file that defines a function called newsfeed().

Here's my plugin code currently: (HOOK: global_complete)

ob_start();
include('magpierss/rss_parse.inc');
newsfeed("http://rss.cnn.com/rss/cnn_topstories.rss",5,"CNN HEADLINES");
$cnn=ob_get_contents();
ob_end_clean();

This is supposed to output an rss feed wherever I call $cnn.

However, what happens, is that the feed shows up at the very top of the page, not where I put the $cnn call.

Is there something I'm not doing properly?

Any help is appreciated.

Thanks in advance.