jQuery add form select value to $_GET value of remote file - php

Question

I was seeking help in a previous threat, and the advice lead me in a different direction. As such, the thread died. I've made a lot of progress, and I feel very close to my answer.
I have two files:
Local file: maps.php
Remote file: maps_append.php
maps.php has a form select tag. I need jQuery to get the value of whatever option is select and load the remote URL (maps_append.php) with maps_append.php?cmd=(value)
What I have is:
<form method="post" action="maps.php">
<td colspan="3">
<select id="cmdview" name="cmd">
<option value=""></option>
<option value="commdata" {if $cmdOn == "commdata"}selected="true"{/if}>Communications</option>
<option value="contacts" {if $cmdOn == "contacts"}selected="true"{/if}>Contacts</option>
<option value="enrollment" {if $cmdOn == "enrollment"}selected="true"{/if}>Enrollment</option>
<option value="all" {if $cmdOn == "all"}selected="true"{/if}>All Schools</option>
</select>
<input type="submit" name="doSwitch" value="Submit" />
</td>
<div id="append"></div2>
</form>
This is my HTML. My jQuery is:
<script>
$('#cmdview').change(function() {
//alert('Handler for .change() called.');
var str = "";
url = "maps_append.php?cmd=str";
$("select option:selected").each(function () {
str += $(this).text() + " ";
});
$.post( url, { cmdview: str } ,
function( data ) {
var content = $( data );
$('#append').load(url);
})
.change();
});
</script>
The problem is my $_GET value (cmd) is always "str". It won't take the value of my select HTML. I can't figure out the syntax for it to great the select value.
All I need is str to = the value of whatever < . option . > is selected
EDIT::
I'd like to add that I know the $.post isn't needed now that I'm doing a _GET value. But, I don't know how else to format this... :(

Answer 1

change
url = "maps_append.php?cmd=str";
to
url = "maps_append.php?cmd=" + str;

Answer 2

Make sure you have proper indentation, or else you are going to get lost quickly. I have cleaned up most of your code. You were hard coding "str" in your url instead of concatenating the variable:
<script>
$('#cmdview').change(function() {
//alert('Handler for .change() called.');
var str = '',
url = 'maps_append.php?cmd=';
$('select option:selected').each(function () {
str += $(this).text() + ' ';
});
url += str;
$.post( url, { cmdview: str } , function( data ) {
var content = $( data );
$('#append').load(url);
}).change();
});
</script>
Also note that you are first doing a POST request to maps_append.php which will have both $_POST['cmdview'] and $_POST['cmd'] set to the options you sent, then once that script has returned a response, you make a GET request by using the load() method, which will then replace the HTML in #append. Not sure why there is that last change() at the end.
From what I can tell, it sounds more like you're trying to do something more like this:
<script>
$('#cmdview').change(function() {
var url = 'maps_append.php?cmd=' + $(this).val();
$.get(url, function(data){
$('#append').append(data);
});
});
</script>

Answer 3

I believe that what you're are trying to accomplish can be resolved with much simpler code. Try replacing your existing JavaScript with this:
$(function() {
$('#cmdview').change(function() {
$('#append').load("maps_append.php?cmd=" + $(this).val());
}).change();
});
This code is simply saying, when you change #cmdview load the contents of the file maps_append.php?cmd= with the value of #cmdview appended to the url. This should make it so you can access the value of #cmdview in your PHP code with $_GET['cmd'].