I'm trying to post a variable through ajax. But it won't echo the variable in php.

This are the variables (these are working, seen in the log):

 $("#slider").bind("valuesChanged", function(e, data){console.log("min: " + data.values.min + " max: " + data.values.max);});

The Ajax part:

$("#slider").bind("valuesChanged", function (e, data) {

  $.ajax({
   type: "POST",
   dataType: "text",
   url: "../test.php",
   data: { minValue: data.values.min, maxValue: data.values.max },
   async: false,
   success: function(data){
      alert('yeah')

    },
     error: function(xhr) {
             alert('fail') // if your PHP script return an erroneous header, you'll land here
            }
 });
});

</script>

And php echo:

<?php

if ( $_POST ) {

        echo $_POST[ 'minValue' ];
            }
?>

Now why does it not echo the post? Thanks!