GOOGLE

<?php
//Include the database configuration file
include 'dbcon.php';
if(!empty($_POST["state_id"])){
    //Fetch all city data
     $query = mysql_query("SELECT * FROM cities WHERE state_id = ".$_POST['state_id']." ORDER BY id ASC");
    //Count total number of rows
    $rowCount = mysql_num_rows($query);
    //City option list
    if($rowCount > 0){
        echo '<option value="">Select city</option>';
        while($row = mysql_fetch_assoc($query)){ 
            echo '<option value="'.$row['id'].'">'.$row['name'].'</option>';
        }
    }else{
        echo '<option value="">City not available</option>';
    }
}
?>