Yahoo RSS search engine

[RobotFX]

Hi!
I have a free script from Scriptol which I use to display feeds content on my site. The script has a form where you can submit a feed url and it will display on the same page the feed rezults. The problems is:
- I want to make it display the Yahoo search results feeds, like a normal search engine, and I don't know how. Basically, the visitors should insert, in the form, only the searched term, not the all yahoo feed url.
The yahoo search feed address is this:

http://api.search.yahoo.com/WebSearchService/rss/webSearch.xml?appid=yahoosearchwebrss&query=search+term&adult_ok=1

where the search term is what I've searched.
Can someone please modify this script for my needs?
I don't know php and I've only tried to add in 2 separate hidden field the http://api.search.yahoo.com/WebSearchService/rss/webSearch.xml?appid=yahoosearchwebrss&query= and the &adult_ok=1, before and after the form search field called dyn, however the script is extracting/displaying only dyn value.
Any help would be apreciated.
Thank you!
This is all the PHP script:

<?php
/*
	RSS Extractor and Displayer
	(c) 2007  Scriptol.com - Licence Mozilla 1.1.
	rsslib.php
	
	Requirements:
	- PHP 5.
	- A RSS feed.
	
	Using the library:
	Insert this code into the page that displays the RSS feed:
	
	<?php
	require_once("rsslib.php");
	echo RSS_Display("http://www.xul.fr/rss.xml", 25);
	?>
	
*/

$RSS_Content = array();

function RSS_Tags($item, $type)
{
		$y = array();
		$tnl = $item->getElementsByTagName("title");
		$tnl = $tnl->item(0);
		$title = $tnl->firstChild->data;

		$tnl = $item->getElementsByTagName("link");
		$tnl = $tnl->item(0);
		$link = $tnl->firstChild->data;

		$tnl = $item->getElementsByTagName("description");
		$tnl = $tnl->item(0);
		$description = $tnl->firstChild->data;

		$y["title"] = $title;
		$y["link"] = $link;
		$y["description"] = $description;
		$y["type"] = $type;
		
		return $y;
}


function RSS_Channel($channel)
{
	global $RSS_Content;

	$items = $channel->getElementsByTagName("item");
	
	// Processing channel
	
	$y = RSS_Tags($channel, 0);		// get description of channel, type 0
	array_push($RSS_Content, $y);
	
	// Processing articles
	
	foreach($items as $item)
	{
		$y = RSS_Tags($item, 1);	// get description of article, type 1
		array_push($RSS_Content, $y);
	}
}

function RSS_Retrieve($url)
{
	global $RSS_Content;

	$doc  = new DOMDocument();
	$doc->load($url);

	$channels = $doc->getElementsByTagName("channel");
	
	$RSS_Content = array();
	
	foreach($channels as $channel)
	{
		 RSS_Channel($channel);
	}
	
}


function RSS_RetrieveLinks($url)
{
	global $RSS_Content;

	$doc  = new DOMDocument();
	$doc->load($url);

	$channels = $doc->getElementsByTagName("channel");
	
	$RSS_Content = array();
	
	foreach($channels as $channel)
	{
		$items = $channel->getElementsByTagName("item");
		foreach($items as $item)
		{
			$y = RSS_Tags($item, 1);	// get description of article, type 1
			array_push($RSS_Content, $y);
		}
		 
	}

}


function RSS_Links($url, $size)
{
	global $RSS_Content;

	$page = "<ul>";

	RSS_RetrieveLinks($url);
	if($size > 0)
		$recents = array_slice($RSS_Content, 0, $size);

	foreach($recents as $article)
	{
		$type = $article["type"];
		if($type == 0) continue;
		$title = $article["title"];
		$link = $article["link"];
		$page .= "<li><a href=\"$link\">$title</a></li>\n";			
	}

	$page .="</ul>\n";

	return $page;
	
}



function RSS_Display($url, $size)
{
	global $RSS_Content;

	$opened = false;
	$page = "";

	RSS_Retrieve($url);
	if($size > 0)
		$recents = array_slice($RSS_Content, 0, $size);

	foreach($recents as $article)
	{
		$type = $article["type"];
		if($type == 0)
		{
			if($opened == true)
			{
				$page .="</ul>\n";
				$opened = false;
			}
			$page .="<b>";
		}
		else
		{
			if($opened == false) 
			{
				$page .= "<ul>\n";
				$opened = true;
			}
		}
		$title = $article["title"];
		$link = $article["link"];
		$description = $article["description"];
		$page .= "<li><a href=\"$link\">$title</a>";
		if($description != false)
		{
			$page .= "<br>$description";
		}
		$page .= "</li>\n";			
		
		if($type==0)
		{
			$page .="</b><br />";
		}

	}

	if($opened == true)
	{	
		$page .="</ul>\n";
	}
	return $page."\n";
	
}


?>
<FORM name="rss" method="POST" action="">
<p>
	<INPUT type="submit" value="Submit">
</p>
  <p>
  <input name="dyn" type="text" size="48" value="">
  </p>
</FORM>
<?php

if (isset( $_POST ))
	$posted= &$_POST ;			
else
	$posted= &$HTTP_POST_VARS ;	


if($posted!= false && count($posted) > 0)
{	
	$url= $posted["dyn"];
	if($url != false)
	{
		echo RSS_Display($url, 15);
	}
}
?>