jQuery variable to php variable then use it on query - php

Question

i have a problem when it comes to retrieving value from jQuery to php.i was able to get the value of my select and pass it to my php but i can't pass it back to php. here is the code...
<script>
$(document).ready(function()
{
$("select#months").change(function(event)
{
var m=$(this).val();
$.ajax({
type: 'POST',
url: "monthly_CRD.php",
data: {m: m},
success: function(){alert("updated")}
});
});
});
</script>
<div>
<select id="months">
<option value='00'>Month...</option>
<option value='01'>Jan</option>
<option value='02'>Feb</option>
<option value='03'>Mar</option>
<option value='04'>Apr</option>
</select>
<select id="years">
<?php
for($yr=10; $yr<=$year; $yr++)
{
echo "<option value='".$yr."'>".$years[$yr]."</option>";
}
?>
</select>
</div>
<?php
if (isset($_POST['m']))
{
$m = $_POST['m'];
echo $m;
} else {echo "fail";}
?>
it keeps on returning fail which means that isset is not working.

Answer 1

Change data: {m: m} to data: {"m":m}
Since you are looking at $_POST['m'] you need to define that key in your JSON. Currently you'd need to look inside $_POST['03'] if you selected Mar

Answer 2

If you mean that on page load, it returns fail, that is because on page load your $_POST array is probably empty.
If you want to know what was returned from your AJAX post, you need your success function to accept a parameter (like data) that jQuery will fill with the response to your post.
Then in the function body, you can write it to the DOM or your error console.

Answer 3

If you have an id to an element then just id is enough to select. Try this
$(document).ready(function()
{
$("#months").change(function(event)
{
$.ajax({
type: 'post',
url: "monthly_CRD.php",
data: { m: $(this).val()},
success: function(){
alert("updated")
}
});
});
});

Answer 4

$(document).ready(function()
{
$("#months").change(function(event)
{
$.ajax({
type: 'post',
url: "monthly_CRD.php",
data: '{ "m": "' + $(this).val() + '"}',
success: function(msg){
alert(msg)
},
error: function(msg) {
alert("An error happened: " +msg);
}
});
});
});
User fiddler of chrome tools to break on either success or error and check the value of the meesage property.