PHP - Moved: Dummy Question: $_get A Varialble When Using Mod_rewrites

I'm having trouble getting my variable to update the database a NULL value. It keeps giving it the value of zero.

This is what I'm using and I've tried it several different ways without luck.

elseif ($item_fee > "1") {
    $sold = NULL;
}

my index.php file includes different files depending on the get value. all of them work except this one:

elseif (isset($_GET['forum']) && $_GET['child']) {

include 'modules/pages/children.php';

}

when i point my browser to index.php?forum=1&child=1 it stays on the same page. Do i need to include something else when getting a url with 2 $_GETs?

This topic has been moved to mod_rewrite.

http://www.phpfreaks.com/forums/index.php?topic=321494.0

This topic has been convinced to move to JavaScript Help of its own free will.

http://www.phpfreaks.com/forums/index.php?topic=345317.0

I'm a beginner with php, but I have a few nifty things working, and I'm trying to enhance my project to do something at the next level.  The project is a library database search tool, and I'm having trouble getting from the search results to the page which shows a record for an individual book.  The search tool works well, and works a few different ways, so I feel I should be able to get this, but this is a first attempt.    I'm stuck on where and how to use $_GET.  If I understand what I need to do, it's something like this:   My search results page has a link as part of the last column:       My first question is, how do I parse this link in php so that it pulls the Id. number from the database, (so that "Link" points to /book.php?0140441638 as a uri?  That column looks something like this:     On the next page, (book.php) which should be the page which shows the information for the individual book, after connecting to my database I have $query="SELECT * FROM MyTable WHERE id='0140441638'".  How would I go about passing the '0140441638' from the referring link?     The next question is how to concatenate this with the openlibrary link in the screenshot -- so that it is passed like src='..//covers.openlibrary.org/b/isbn/**RESULT**-L.jpg' />   Thank you to anyone who can help me with this!