I hope the following code will help or solve your problem or you think not that understandable visit http://phppot.com/jquery/jquery-dependent-dropdown-list-countries-and-states/.
HTML DYNAMIC DEPENDENT SELECT
<div class="frmDronpDown">
<div class="row">
<label>Country:</label><br/>
<select name="country" id="country-list" class="demoInputBox" onChange="getState(this.value);">
<option value="">Select Country</option>
<?php
foreach($results as $country) {
?>
<option value="<?php echo $country["id"]; ?>"><?php echo $country["name"]; ?></option>
<?php
}
?>
</select>
</div>
<div class="row">
<label>State:</label><br/>
<select name="state" id="state-list" class="demoInputBox">
<option value="">Select State</option>
</select>
</div>
GETTING STATES VIA AJAX
<script> function getState(val) { $.ajax({
type: "POST",
url: "get_state.php",
data:'country_id='+val,
success: function(data){
$("#state-list").html(data);
}
});} </script>
READ STATE DATABASE USING PHP
<?php require_once("dbcontroller.php"); $db_handle = new DBController();if(!empty($_POST["country_id"])) {
$query ="SELECT * FROM states WHERE countryID = '" . $_POST["country_id"] . "'";
$results = $db_handle->runQuery($query); ?> <option value="">Select State</option><?php foreach($results as $state) { ?> <option value="<?php echo $state["id"]; ?>"><?php echo $state["name"]; ?></option><?php } } ?>