php combo boxes

WebHelper Joined: 15 Jan 2004 Posts: 91

I have two combo boxes on the same page and am using a PHP function to load the values into them.

To make the script more workable I would like to select the first one which lists “crags” and when that is selected I want the other combo box to only display climbs from the crag selected in the first box.

I have thought about using JavaScript (on change), but I was wondering if I could just use PHP to find out the first value and reload the second combo box.

I am not sure how to go about this and would like to look at some working code that does something similar.

Can anyone point me in the correct direction?

I have enclosed my code thus far for your information

The function to load the combo box

Code:

Check the data and query the database (ignore escape_data fn)

Code:

$page_title = 'climbers_climbes';
include ('templates/header.inc');

if (isset($_POST['submit']))
{
require_once ('../../mysql_connect.php'); // Connect to the db.

$message = NULL; // Create an empty new variable.

//_________________________________________________________________________

if ($_POST['climb_id'] == 1) // the form initial set condition and the first record in the database
   {
   $cid = FALSE;
   $message .= '<p>You did not enter the climb </p>';
   }
else
   {
   $cid = escape_data($_POST['climb_date']);
   }
// if ($_POST['crag_id'] == 1) // the form initial set condition and the first record in the database
//       {
//    $crag = FALSE;
//    $message .= '<p>You did not enter the crag</p>';
//    }
// else
//    {
//    $crag = escape_data($_POST['crag_id']);
//    }

//_________________________________________________________________________ if form data is ok
if ( $cid) //if $fn and $cid etc is not false continue
{ //start of if

   // process form
   require_once ('../../mysql_connect.php'); // http dir
   $query = “blar blar blar";
   $result = @mysql_query($query);

if ($result)
   {
   echo 'your data was passed to the database';
include ('templates/footer.inc'); // Include the HTML footer.
   exit();
   }
else
   {
   $message = 'your data was not passed due to a system error';
   }

   mysql_close();
}// end of if

else
{
$message .='please try again';
}

} //end of submit

if (isset($message))
   {
echo '<font color="red">', $message, '</font>';
}

?>

Part of the form to build the combo boxes

Code:

<form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post">

<p>Crags
<?php
enhanced_list_box_crags(array(
'table' => 'crags',
'id_field' => 'crag_id',
'value_field' => 'crag_name',
'highlight_id' => 1));

?>

<p>Climb
<?php

enhanced_list_box(array(
'table' => 'climb_details',
'id_field' => 'climb_id',
'value_field' => 'climb_name',
'highlight_id' => 1));
?>

<input type="Submit" name="submit" value="Enter information" />

</form>
</font>

[/code]

Team Member Joined: 06 Jan 2002 Posts: 2564

I would actually do it with Javascript, since I find having forms reloaded while I'm filling them in is annoying. Also you'll have to use Javascript anyway to reload the page Smile

http://forums.devshed.com/archive/t-128656 talks about ways of doing this with Javascript.

WebHelper Joined: 15 Jan 2004 Posts: 91

Thanks again Daniel.