Related dropdown using javascript and php - php

Question

I have this script and I want to get the value of drop down select list in the PHP and check the if (jws1 != "") then show 1 to 10 value in the second drop down box using of for loop...
JavaScript code:
<script language="javascript" type="text/javascript">
function test()
{
var e = document.getElementById("JWSections");
var Sections = e.options[e.selectedIndex].value;
alert(Sections);
}
</script>
HTML code:
<select name="JWSections" id="JWSections" onchange="test();">
<option value="">Select Sections</option>
<option value="jws1">Section 1.1</option>
<option value="jws2">Section 1.2</option>
<option value="jws3">Section 1.3</option>
<option value="jws4">Section 1.4</option>
</select>
I want to get the value like jws1, and check in the PHP.

Answer 1

For PHP to be able to do anything with your HTML form data, you'll have to submit it to PHP.
You can either submit the form itself or use AJAX to pass in the value of jws1 and build the options from the result. Jquery is pretty good with doing that kind of thing, all you gotta do is set your AJAX request's data type to HTML and assign the data from the "success" callback to your destination drop down list.

Answer 2

<select name="JWSections" id="JWSections" onchange="test(this);">
<option value="">Select Sections</option>
<option value="jws1">Section 1.1</option>
<option value="jws2">Section 1.2</option>
<option value="jws3">Section 1.3</option>
<option value="jws4">Section 1.4</option>
</select>
<select name="JWSections" id="secondDropDown"> </select>
<script language="javascript" type="text/javascript">
function test(dropdown)
{
var selectedjws = dropdown.options[dropdown.selectedIndex].value;
var secondDropDown = document.getElementById('secondDropDown');
$.post('path', { selectedjws : selectedjws }, function(key, value){
// Remove all options from second dropdown
for(var i = 0; i < secondDropDown.options.length; i++){
secondDropDown.remove(i);
}
// Add options by key value pair returned from server
secondDropDown.add(new Option(value, key))
});
}
</script>
jsfiddle: http://jsfiddle.net/KTq6y/1/