type_child.php

<?php
    include_once 'dbconfig.php';
	if($_POST['type_top'])
	{
 		$type_top=$_POST['type_top'];
		$query = "SELECT * FROM type_child WHERE type_top='$type_top'" ;
        $result = mysqli_query($connection,$query) ;
 ?>
 	<option selected="selected">Select State :</option>
 	<?php
 		while($row = mysqli_fetch_array($result))
 		{
  	?>
        		<option value="<?php echo $row['type_child']; ?>">
        			<?php 
        				echo $row['type_child_name']; 
        			?>
        		</option>
        	<?php
 		}
	}
?>