Selected index changed event in jquery using asp.net

Question

I dont have any error and I dont know where my mistake is, could somebody please help me to solve this problem?

$(document).ready(function () {

           $('#Ddl').change(function () {

var Text;

var Value;

               Text = $(this).find(":selected").val();

               Value = $(this).val();

              alert("Text is"+Text +" and value is "+Value +");

 

           });

       });