Jquery ajax call is not calling controller in codeigniter

Question

I am trying to call my controller function using ajax but it is not calling with input . Here is my ajax call

 if(value)
            {
               $.ajax({
                   type:"POST",
                   dataType:"text",
                   cache:false,
                   contentType: "application/json; charset=utf-8",
                   url:"<?php echo base_url('Dashboard/deleteSpeciality'); ?>",
                   data:{'id':id},
                   success:function(data){
                       alert("i am in success");
                   },
                   error:function(data){
                       alert(data);
                   }
               });
            }

and here is my controller function. Ajax call is going but input is not. At server side program throws error Id is not defined.

  public function deleteSpeciality($id) {
        $result= $this->Dashboard_model->getSpeciality($id);
        $path=$result[0]->ImagePath;
        $this->load->helper("file");
        delete_files($path);
        unlink($path); 
        $this->Dashboard_model->deleteSpeciality($id);
        return 1;
    }

Answer 1

Try this in your controller $id=$_POST['id'] and as you are using Post method so don't pass id as parameter in function.

public function deleteSpeciality() {
        $id=$_POST['id']
        //code here
    }

Answer 2

Try this

 public function deleteSpeciality()
    {
      $id=$this->input->post('id');
      // will print the id that was posted from ajax 
      //echo $id; 
      $result= $this->Dashboard_model->getSpeciality($id);
      $path=$result[0]->ImagePath;
      $this->load->helper("file");
      delete_files($path);
      unlink($path); 
      $this->Dashboard_model->deleteSpeciality($id);
      return 1;
    }