<html>
<head>
<title>Test</title>
</head>
<body>
<table>
<?php
// do mysql connection with mysql_connect() and mysql_select_db
$instruments = $_GET['Instrument_ID'];
$query = "SELECT * FROM artists WHERE Instrument_ID IN ($instruments)";
$result = mysql_query($query);
while ($row = mysql_fetch_assoc($result)) {
echo "<tr>\n";
echo "<td>".$row['id_usr']."</td>\n";
echo "<td>".$row['id_name_usr']."</td>\n";
echo "<td>".$row['Instrument_ID']."</td>\n";
// and so on for other fields
echo "</tr>\n";
}
?>
</table>
</body
</html>
//in your search page
<form action="yoursearchresultspage.php" method="get">
<input type="checkbox" name="Instrument_ID[]" value="1"/> <label>Cello</label><br/>
<input type="checkbox" name="Instrument_ID[]" value="2"/> <label>Guitar</label><br/>
<input type="checkbox" name="Instrument_ID[]" value="3"/> <label>Piano</label><br/>
<input type="checkbox" name="Instrument_ID[]" value="4"/> <label>Violin</label><br/>
<input type="submit" value="Search"/>
</form>
$result = mysql_query($query);
<input type=checkbox name="Instrument_ID[]" value="1" />
<input type=checkbox name="Instrument_ID[]" value="2" />
<input type=checkbox name="Instrument_ID[]" value="3" />
if(isset($Instrument_ID))
{
$Instruments= join(",", $Instrument_ID);
}