Adding another layer to this script?

[Perad]

I found this script a while back and have used a modified version of this is used across my new site. The problem i am having is that i need to add another layer to it and don't understand how the switch statement that controls it works.

Here's the script

[code]<?php
/* user config variables */
$max_items = 5; /* max number of news items to show */

/* make database connection */
$db = mysql_connect ('localhost','root','Berskin99');
mysql_select_db ('test',$db);

function displayNews($all = 0) {
    /* bring in two variables
    * $db is our database connection
    * $max_items is the maximum number
    * of news items we want to display */
    global $db, $max_items;
   
    /* query for news items */
    if ($all == 0) {
        /* this query is for up to $max_items */
        $query = "SELECT id,title,newstext," .
                "DATE_FORMAT(postdate, '%Y-%m-%d') as date " .
                "FROM news ORDER BY postdate DESC LIMIT $max_items";
    } else {
        /* this query will get all news */
        $query = "SELECT id,title,newstext," .
                "DATE_FORMAT(postdate, '%Y-%m-%d') as date " .
                "FROM news ORDER BY postdate DESC";
    }
    $result = mysql_query ($query);
    while ($row = mysql_fetch_assoc ($result)) {
        /* display news in a simple table */
        echo "<TABLE border=\"1\" width=\"300\">\n";

        /* place table row data in
        * easier to use variables.
        * Here we also make sure no
        * HTML tags, other than the
        * ones we want are displayed */
        $date = $row['date'];       
        $title = htmlentities ($row['title']);
        $news = nl2br (strip_tags ($row['newstext'], '<a><b><i><u>'));
       
        /* display the data */
        echo "<TR><TD><b>$title</b> posted on $date</TD></TR>\n";
        echo "<TR><TD>$news</TD></TR>\n";
       
        /* get number of comments */
        $comment_query = "SELECT count(*) FROM news_comments " .
                        "WHERE news_id={$row['id']}";
        $comment_result = mysql_query ($comment_query);
        $comment_row = mysql_fetch_row($comment_result);
       
        /* display number of comments with link */
        echo "<TR><TD><a href=\"{$_SERVER['PHP_SELF']}" .
            "?action=show&id={$row['id']}\">Comments</a>" .
            "($comment_row[0]}</TD></TR>\n";
       
        /* finish up table*/
        echo "</TABLE>\n";
        echo "<BR>\n";
    }
   
    /* if we aren't displaying all news,
    * then give a link to do so */
    if ($all == 0) {
        echo "<a href=\"{$_SERVER['PHP_SELF']}" .
            "?action=all\">View all news</a>\n";
    }
}

function displayOneItem($id) {
    global $db;
   
    /* query for item */
    $query = "SELECT * FROM news WHERE id=$id";
    $result = mysql_query ($query);
   
    /* if we get no results back, error out */
    if (mysql_num_rows ($result) == 0) {
        echo "Bad news id\n";
        return;
    }
    $row = mysql_fetch_assoc($result);
    echo "<TABLE border=\"1\" width=\"300\">\n";

    /* easier to read variables and
    * striping out tags */
    $title = htmlentities ($row['title']);
    $news = nl2br (strip_tags ($row['newstext'], '<a><b><i><u>'));
   
    /* display the items */
    echo "<TR><TD><b>$title</b></TD></TR>\n";
    echo "<TR><TD>$news</TD></TR>\n";
   
    echo "</TABLE>\n";
    echo "<BR>\n";
   
    /* now show the comments */
    displayComments($id);
}

function displayComments($id) {
    /* bring db connection variable into scope */
    global $db;
   
    /* query for comments */
    $query = "SELECT * FROM news_comments WHERE news_id=$id";
    $result = mysql_query ($query);
    echo "Comments:<BR><HR width=\"300\">\n";
   
    /* display the all the comments */
    while ($row = mysql_fetch_assoc ($result)) {
        echo "<TABLE border=\"1\" width=\"300\">\n";
       
        $name = htmlentities ($row['name']);
        echo "<TR><TD><b>by: $name</b></TD></TR>\n";
   
        $comment = strip_tags ($row['comment'], '<a><b><i><u>');
        $comment = nl2br ($comment);
        echo "<TR><TD>$comment</TD></TR>\n";
   
        echo "</TABLE>\n";
        echo "<BR>\n";
    }
   
    /* add a form where users can enter new comments */
    echo "<HR width=\"300\">";
    echo "<FORM action=\"{$_SERVER['PHP_SELF']}" .
        "?action=addcomment&id=$id\" method=POST>\n";
    echo "Name: <input type=\"text\" " .
        "width=\"30\" name=\"name\"><BR>\n";
    echo "<TEXTAREA cols=\"40\" rows=\"5\" " .
        "name=\"comment\"></TEXTAREA><BR>\n";
    echo "<input type=\"submit\" name=\"submit\" " .
        "value=\"Add Comment\"\n";
    echo "</FORM>\n";
   
}

function addComment($id) {
    global $db;
   
    /* insert the comment */
    $query = "INSERT INTO news_comments " .
            "VALUES('',$id,'{$_POST['name']}'," .
            "'{$_POST['comment']}')";
    mysql_query($query);
   
    echo "Comment entered. Thanks!<BR>\n";
    echo "<a href=\"{$_SERVER['PHP_SELF']}" .
        "?action=show&id=$id\">Back</a>\n";
}

/* this is where the script decides what do do */

echo "<CENTER>\n";
switch($_GET['action']) {
   
    case 'show':
        displayOneItem($_GET['id']);
        break;
    case 'all':
        displayNews(1);
        break;
    case 'addcomment':
        addComment($_GET['id']);
        break;
    default:
        displayNews();
}
echo "</CENTER>\n";
?> [/code]

I have written what i want to add which you can see below. Each news article has a category. I want the user to be able to select a category which will lead them onto the news in that category. How would i modify the switch statement to allow this?

[code]<? function displayArticles() {

global $dbc, $max_items, $username;
$query = "SELECT * FROM site_categories";
$result = mysql_query ($query);
while ($row = mysql_fetch_assoc ($result)) {
/* display categories in a simple table */
echo "<TABLE border=\"1\" width=\"580\">\n";
 
$title = htmlentities ($row['cat_name']);
echo "<TR><TD width=\"300\"><b>$title</b></TD>";

/* get number of articles */
$comment_query = "SELECT count(*) FROM downloads WHERE cat_id={$row['cat_id']}";
$comment_result = mysql_query ($comment_query);
$comment_row = mysql_fetch_row($comment_result);

/* display number of articls with link */
echo "<TD><a href=\"{$_SERVER['PHP_SELF']}" .
"?action=show&cat_id={$row['cat_id']}\">Articles</a>" .
"($comment_row[0])</TD></TR>\n";

/* finish up table*/
echo "</TABLE>\n";
echo "<BR>\n";
}
}?>[/code]