Auto complete with json assistance

Hi
I’ve been trying to customise a script i found for an autocomplete search field using a php mysql query.
The php file is below, it’s searching mobile phone make and models, all works but when i search sam for Samsung i get nothing unless i search Sam

So my first question is can i change (with your help) the search code in the PHP to not be case sensitive?

also if i search Samsung D600 it finds the phone but i’d like it to find this phone if i just type D600, could this be a possibility with this code?

<?php

require “dbcommon.php”;
$result = mysql_query(“SELECT* FROM handsets”);
while ($row = mysql_fetch_assoc($result)) {
$handsets[] = $row[‘product_name/handset’];
}
mysql_free_result($result);
// check the parameter
if(isset($_GET[‘part’]) and $_GET[‘part’] != ‘’)
{
// initialize the results array
$results = array();

// search handsets
foreach($handsets as $handset)
{
	// if it starts with 'part' add to results
	if( strpos($handset, $_GET['part']) === 0 ){
		$results[] = $handset;
	}
}

// return the array as json with PHP 5.2
echo json_encode($results);

}
?>

thanks for any help given