//Index.php
<?php
$conn = mysql_connect("localhost", "root", "root");
$db = mysql_select_db("country_example", $conn);
$sql_country = "SELECT * FROM country";
$result_country = mysql_query($sql_country);
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>Country List</title>
</head>
<body>
<?php
echo "<select name='country' onChange='get_cities(this.value)'>";
while($row_country = mysql_fetch_array($result_country))
{
echo "<option value='".$row_country['id']."'>".$row_country['country']."</option>";
}
echo "</select>";
echo "<div id='cityLayer'><select name='city' id='city'></select></div>";
?>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script type="text/javascript">
function get_cities($country_id){
$.ajax({
url : "city.php?country_id="+$country_id,
cache : false,
beforeSend : function (){
//Show a message
},
complete : function($response, $status){
if ($status != "error" && $status != "timeout") {
$('#cityLayer').html($response.responseText);
}
},
error : function ($responseObj){
alert("Something went wrong while processing your request.\n\nError => "
+ $responseObj.responseText);
}
});
}
</script>
</body>
</html>
//City.php
<?php
$conn = mysql_connect("localhost", "root", "root");
$db = mysql_select_db("country_example", $conn);
$country_id = $_REQUEST['country_id'];
$sql_city = "SELECT * FROM cities WHERE country_id = '".$country_id."'";
$result_city = mysql_query($sql_city);
echo "<select name='city'>";
while($row_city = mysql_fetch_array($result_city))
{
echo "<option value='".$row_city['id']."'>".$row_city['city']."</option>";
}
echo "</select>";
?>
