通过键入url加载页面时，Ajax无法正常工作。 但如果通过单击其他页面上的链接加载页面，则工作正常

Question

In my header.php file I have many jQuery functions like change form on button click.

Everything is working fine, but two jQuery functions, that have ajax involved, do not work fine when I load the page by typing link in the browser. But they work fine when I load the page by clicking on the link on other page.

Here is my jquery code :

<script>

$(document).ready(function(){
  $('#email_s').change(function(){
    var email = $('#email_s').val();
    if(email != '')
    {
      $.ajax({
        url:"<?php echo base_url(); ?>Home/checkuser",
        method:"POST",
        data:{email:email},
        success:function(data){
          $('#emailseller_result').html(data);
        }
      });
    }
  });
  $('#username_s').change(function(){
    var username = $('#username_s').val();
    if(username != '')
    {
      $.ajax({
        url:"<?php echo base_url(); ?>Home/checkusername",
        method:"POST",
        data:{username:username},
        success:function(data){
          $('#userseller_result').html(data);
        }
      });
    }
  });
});

</script>