Cascade Drop Down

I need a quick solution to this;

I am making a form that has 3 drop downs. The first drop down you select region, the second and 3rd drop down gets populated with hotels in the respect regions.

It would help if no refresh is required or if we have the "select region first" for dropdown 2 and dropdown 3.
bernsoftAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

PHPeZCommented:
Ok,
let me try to help:

Dropdowns on the form:
 - Have them in a container with unique id assigned. eg. <div> tags.
you might already have something like (i'm emphasizing on the functional part more):

<form............>
<div id="regionDiv">
<select name="regionDD" id="regionDD" onChange="populateHotel(this.value);">
<?php
   $query = mysql_query("SELECT `id`,`regionName` FROM `regionsTable`");
   while($obj=mysql_fetch_object($query))
   {
  ?>
   <option value="<?php echo $obj->id;?>"><?php echo $obj->regionName;?></option>
<?php
  }
 ?>
</select>
</div>

Similarly, you'd have dummy dropdowns for the hotel:
I'm doing just one dropdown, you could use it to create the third dropdown.

<div id="hotelDiv1">
<select name="hotelDD" id="hotelDD">
<option value="-1">--Select hotel--</option>
</select>
</div>

=============================================
The above would do for the interface. Now what you'd need is the function to populate the div with hotels.

I'm using Ajax below (referring to "no refresh is required"):
<script type="text/javascript">

function createObject() {
var request_type;
var browser = navigator.appName;
if(browser == "Microsoft Internet Explorer"){
request_type = new ActiveXObject("Microsoft.XMLHTTP");
}else{
request_type = new XMLHttpRequest();
}
return request_type;
}

var data = createObject();



function populateHotel(id)
{
            
var xmlhttp = getHTTPObject();
var file = 'getHotel.php?regionid='+id; //This is the path to the php file which has the code to output the hotels.*

xmlhttp.open('GET', file, true); //Open the file through GET, and add the page to retrieve as a GET variable **
xmlhttp.onreadystatechange=function()
      {
      
      if (xmlhttp.readyState==4) { //Check if it is ready to recieve data
         var content = xmlhttp.responseText; //The content data which has been retrieved ***
      
                  if(content){ //Make sure there is something in the content variable
      
                            document.getElementById('hotelDiv1').innerHTML = content;  //Change the inner content of your div to the newly retrieved content ****
      
                        }
                            }
      }
xmlhttp.send(null) //Nullify the XMLHttpRequest
return;
}
</script>
========================================================================
Now you'd have to have the file getHotel.php created and placed on the same folder as the above file is (note that i've written the ajax script on the same file as the dropdowns are, its better you create a separate .js file and use src attribute on <script> opening tag to make a call to the .js file).

Below is the code which should give you the hotels:
<?php
$regionId = $_GET[id]; // the id passed from the ajax script. :)
$queryHotel = mysql_query("SELECT `id`,`hotelName`  FROM `hotelsTable` WHERE `region`='".$regionId."'");
?>
<select name="hotelDD" id="hotelDD">
<option value="-1">--Select hotel--</option>
<?php
while($hotelObj=mysql_fetch_object($queryHotel))
{
?>
  <option value="<?php echo $hotelObj->id;?>"><?php echo $hotelObj->hotelName;?></option>
<?php
}
?>


=========
 I just did that on notepad..donno if I have some typos there, but I'm sure you'd fix it. The rest of the logic and code should work for you.

Cheers!
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
bernsoftAuthor Commented:
Thanks i will try this and get back to you.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
AJAX

From novice to tech pro — start learning today.