Firstly, let me say that I've been searching the Internet, rewriting scripts and I still can't seem to find a solution to my problem or even one that could possibly help. I've even searched this site for similar questions and the focus seems to be on actually displaying the database values but what I want is to access those values. Or rather let me put it like this, I have a drop down that is generated through php and it contains data retrieved from mysql... all that works fine no errors.
My current problem is that when a user select an option from my dropdown, I want to use that value to do more operations based on the user's selection. Please help, I've been at it for a week with no avail. Thanks in advance. If you need samples of my code please tell me.
Your problem is not that easy since php only runs on the server and does not directly get any information about what a user is clicking and selecting in his browser.
One possible solution (and the most common one nowadays) is to load any further information asynchronously via AJAX as soon as the user selects something in your dropdown. jQuery is a neat framework that can help you with this.
An other method is to automatically submit the form as soon as something is selected and read the selected value with php ($_POST variable). With this you could then easily generate a more custom website according to the selection that was made. Code could look like this:
<form method="post" action="" name="myform">
<select name="myfield" onchange="this.form.submit()">
<option .... >
...
</select>
</form>
(Note that the form is submitted when the onchange event is triggered)
This method clearly has the disadvantage that the whole page has to be reloaded whenever a selection is made. With the AJAX approach the user does not even notice that some additional information was fetched form the server. (Except a small waiting time that may occur)
What you want to do depends on your own decisioin. However the first approach may need you to get into some javascript programming. But the result is certainly more comfortable for the user...
You could make a callback function on the onselect Event. This is the easiest with jQuery in my experience.
Wrap your select in a form which had a post of type 'get'. This will post to the same page you are in and then you can use the get parameter on page refresh to load your second list