website developed with codeigniter working well on localhost but internal server error 500 on live server

website developed with codeigniter working well on localhost but internal
server error 500 on live server

I am newbie to codeigniter i am developed a website from past few days.
The website working well on the localhost.but when i tested that that
website on live web server i gives out following error:
500 - Internal server error. There is a problem with the resource you are
looking for, and it cannot be displayed. i tried a lot of things like
.htaccess solutions available on different tutorials but not successful.
Then i tried my self debugging and found that when i comment out the model
loading line my index page get loaded without that data to have to get
from the db.But as soon as i remove comment from that line it again gives
me the same error. Then i checked my model i wont find any such
problem.Now i am not using any .htaccess. PHP version on server:5.2.17
codeigniter version:CodeIgniter_2.1.4
------------------------My code for controller
is---------------------------------
<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');?>
<?php
class video extends CI_Controller
{
function __construct()
{
parent::__construct();
$this->load->helper('url');
$this->load->model('video_model');
$this->load->helper('html');
$this->load->library('session');
}
function index()
{
$this->session->unset_userdata('searchterm');
$data['latest_video']=$this->latest_video();
$data['uk_video']=$this->uk_video();
$data['hm_video']=$this->hm_video();
$this->load->view('index',$data);
}
function watch()
{
$v_type=$this->uri->segment(3);
$v_id=$this->uri->segment(4);
if($v_type && $v_id)
{
$data['multiple_videos']=$this->video_model->get_all_videos($v_type);
$data['single_video']=$this->video_model->get_single_video($v_id,$v_type);
$counter= $data['single_video'][0]['counter'];
$id= $data['single_video'][0]['v_id'];
$this->load->view('watch',$data);
$this->view_counter($id,$counter);
}
else
{
redirect('video','refresh');
}
}
function latest_video()
{
$data[]=$this->video_model->get_latest_video();
return $data;
}
function uk_video()
{
$data[]=$this->video_model->get_uttrakhand_video();
return $data;
}
function hm_video()
{
$data[]=$this->video_model->get_himachal_video();
return $data;
}
function result()
{
$this->load->view('search');
}
function view_counter($id,$counter)
{
$user_ip=$this->input->ip_address();
if(!$this->input->cookie($id))
{
$cookie=array('name'=>$id,'value'=>$user_ip,'expire'=>43200);
$this->input->set_cookie($cookie);
$counter++;
}
if($this->input->cookie($id))
{
if($this->input->cookie($id,TRUE)!=$user_ip)
{
$counter=+$counter;
}
}
$update=array('counter'=>$counter);
$this->db->where('v_id',$id);
$this->db->update('tblvideo',$update);
}
}
?>
------------------------My code for Model is---------------------------------
<?php class video_model extends CI_Model
{
function __construct()
{
parent::__construct();
$this->load->database();
}
function get_latest_video()
{
$this->db->select('v_id,v_name,v_title,v_description,v_image,v_type,v_duration,v_time,counter')->from('tblvideo')->order_by('v_time','DESC')->limit(3);
$query=$this->db->get();
return $latest_data=$query->result_array();
}
function get_uttrakhand_video()
{
$this->db->select('v_id,v_name,v_title,v_description,v_image,v_type,v_duration,v_time,counter')->from('tblvideo')->where('v_type','uk')->order_by('v_time','DESC')->limit(4,3);
$query=$this->db->get();
return $latest_data=$query->result_array();
}
function get_himachal_video()
{
$this->db->select('v_id,v_name,v_title,v_description,v_image,v_type,v_duration,v_time,counter')->from('tblvideo')->where('v_type','hm')->order_by('v_time','DESC')->limit(4,3);
$query=$this->db->get();
return $latest_data=$query->result_array();
}
function insert_data()
{
$data=array(
'v_title'=>$this->input->post('v_title'),
'v_name'=>$this->input->post('v_name'),
'v_description'=>$this->input->post('v_description'),
'v_tags'=>$this->input->post('v_tags'),
'v_duration'=>$this->input->post('v_duration'),
'v_type'=>$this->input->post('v_type')
);
return $this->db->insert('tblvideo',$data);
echo "data inserted";
}
function get_single_video($v_id,$v_type)
{
$cond=array('v_id'=>$v_id,'v_type'=>$v_type);
$this->db->select('v_id,v_name,v_title,v_description,v_image,v_type,v_duration,v_time,counter')->from('tblvideo')->where($cond);
$res=$this->db->get();
return $res->result_array();
}
function get_all_videos($v_type)
{
$this->db->select('v_id,v_name,v_title,v_description,v_image,v_type,v_duration,v_time,counter')->from('tblvideo')->where('v_type',$v_type)->order_by('v_time','DESC')->limit(30);
$query=$this->db->get();
return $query->result_array();
}
function get_video_list($limit,$offset)
{
$offset=intval($offset);
$this->db->select('v_id,v_name,v_title,v_description,v_tags,v_image,v_type,v_duration,v_time,counter')->from('tblvideo')->order_by('v_time','DESC')->limit($limit,$offset);
$query=$this->db->get();
return $query->result_array();
}
function get_total_number_videos()
{
$this->db->select('v_id,v_name,v_title,v_description,v_tags,v_image,v_type,v_duration,v_time,counter')->from('tblvideo')->order_by('v_time','DESC');
$query=$this->db->get();
return $query->num_rows();
}
function video_edit($v_id)
{
$this->db->select('v_id,v_name,v_title,v_description,v_image,v_tags,v_type,v_duration,v_time')->from('tblvideo')->where('v_id',$v_id);
$query=$this->db->get();
return $query->result_array();
}
function video_update($id,$table,$form_data)
{
$this->db->where('v_id',$id);
return $response=$this->db->update($table,$form_data);
}
function delete($id,$table)
{
$this->db->delete($table, array('v_id' => $id));
}
function user_authentication($u_name,$pwd)
{
$array=array('username'=>$u_name,'password'=>$pwd,'type'=>'admin');
$this->db->select('username,password,id,type')->from('tblusers')->where($array);
$query=$this->db->get();
return $query->num_rows();
}
function user_data($u_name,$pwd)
{
$array=array('username'=>$u_name,'password'=>$pwd,'type'=>'admin');
$this->db->select('username,password,id,type')->from('tblusers')->where($array);
$query=$this->db->get();
return $query->result_array();
}
}?>
please take look at the problem thank you...