search and results problem

[charter]

Can any of the gurus out there please help?
I am having a search problem with PHP and MySQL.

I wish to search the MySql database from 2 criteria.
Using 2 dropdown boxes.

I wish to search from 1 dropdown box called searchtype and another called searchterm. The problem is I cannot get them to work do a proper search.
I can get it to work using just one search criteria but I want the result to be of both criteria being true.

This is the form code for the search:

Search: 
20002001200220032004
  

12345
  

This is the code for the results page:

<?php
// create short variable names

if(ini_get('register_globals') != "1")
{
$post = (floatval(substr(phpversion(), 0, 3)) >= 4.1) ? $_POST : $HTTP_POST_VARS;

foreach($post as $key => $value)
{
$$key = $value;
}
}
$searchtype = addslashes(trim($searchtype));
$searchterm = addslashes(trim($searchterm));

if(!$searchtype || !$searchterm)
{
exit('You have not entered search details. Please go back and try again.');
}
$link_id = @mysql_connect("localhost", "root", "password");

if($link_id === false)
{
exit("Error, Could not connect to the system database. Sorry...");
}
mysql_select_db('charts50', $link_id);
$result = mysql_query("SELECT * FROM `usa` WHERE `{$searchtype}` LIKE '%{$searchterm}` LIKE %'");
?>

50 YEARS AGO TW LW Wks Title Artist <?php $i = 1; while($row = mysql_fetch_array($result)){

$item = array();
$item['tw'] = stripslashes($row['tw']);
$item['lw'] = stripslashes($row['lw']);

// now we can override that $item['lw'] = ($item['lw']=='new') ? "" : $item['lw'];

$item['wks'] = stripslashes($row['wks']);
$item['title'] = strtoupper(stripslashes($row['title']));
$item['artist'] = stripslashes($row['artist']);
?>

<?php echo $item['tw']; ?>
<?php echo $item['lw']; ?>
<?php echo $item['wks']; ?>
<?php echo $item['title']; ?>
<?php echo $item['artist']; ?>

<?php $i++; } ?>

I want the results to be true of both searchtype and searchterm.

If someone could please help by amending the correct code or tell me what I should amend on either the search form or the results code or both. That is true to year and wk no.
I have put 'password' just for this post.

All help is very much appreciated.