Example Explained

The stateChanged() and GetXmlHttpObject functions are the same as in the PHP AJAX Suggest chapter, you can go to there for an explanation of those.

The showUser() Function

If an item in the drop down box is selected the function executes the following:

The PHP Page

The server page called by the JavaScript, is a simple PHP file called "getuser.php".
The page is written in PHP and uses a MySQL databse.
The code runs a SQL query alongside a database and returns the result as an HTML table:

<?php
$q=$_GET["q"];
$con = mysql_connect('localhost', 'peter', 'abc123');
if (!$con)
 {
 die('Could not connect: ' . mysql_error());
 }
mysql_select_db("ajax_demo", $con);
$sql="SELECT * FROM user WHERE id = '".$q."'";
$result = mysql_query($sql);
echo "<table border='1'>
<tr>
<th>Firstname</th>
<th>Lastname</th>
<th>Age</th>
<th>Hometown</th>
<th>Job</th>
</tr>";
while($row = mysql_fetch_array($result))
 {
 echo "<tr>";
 echo "<td>" . $row['FirstName'] . "</td>";
 echo "<td>" . $row['LastName'] . "</td>";
 echo "<td>" . $row['Age'] . "</td>";
 echo "<td>" . $row['Hometown'] . "</td>";
 echo "<td>" . $row['Job'] . "</td>";
 echo "</tr>";
 }
echo "</table>";
mysql_close($con);
?>

Example Explained

When the query is sent from the JavaScript to the PHP page the following happens:

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