No value in the call back - Jason - Jquery

[eluser]Shiju S S[/eluser]

Code:

<$cript>
var base_url = "&lt;?php echo base_url();?&gt;";
$('#tags').change(function()
{
var jqxhr = $.getJSON(base_url + "franchisee_lab_investigations/get_patient_details", function(data) {
  alert(data);
})

});
</$cript>

I get an output object object