Password Change module - CI

pwdchange

My View

<form action="" method="POST" id="pwdchange">
                        <span><h2 style="font-family:'Ubuntu',sans-serif;" align="justify">Change your Password here</h2><br /></span>
                                    <?php echo form_open('users/passwordchange');?>
                                    Current Password:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
                                    <?php $data=array('id'=>'oldpwd','name'=>'oldpwd','class'=>'span4','type'=>'password','placeholder'=>'Old Password');
                                    echo form_input($data); ?><br /><br />                          
                                    New Password:
                                    <?php $data2=array('id'=>'newpwd','name'=>'newpwd','class'=>'span4','type'=>'password','placeholder'=>'New Password');
                                    echo form_input($data2);    ?><br /><br />
                                    Password:
                                    <input type="submit" class="btn primary large" style="font-family:'Ubuntu',sans-serif;" id="submitbtn" value="Change my Password"></input>
                                    
                                <?=form_close();?>
                    </form>

My Controller

public function passwordchange()

		{
			
			$this->load->model('users');

			$oldpwd = $this->input->post('oldpwd');
			$newpwd = $this->input->post('newpwd');

			$flag = $this->users->pwdchange($oldpwd,$newpwd);

			if($flag == TRUE)

			{
				echo "password changed";
			}

			else
			{
				echo "failed";
			}



		}

My Model

public function pwdchange($oldpwd,$newpwd)
    {
        $this->load->database();
        
        if(md5($oldpwd) == $this->session->userdata('password'))
        	
	        {
	        		
	        		$npwd = md5($newpwd);
	        		$data = array('password' = $npwd);
	        		$uid  = $this->session->userdata('id');
	        		$this->db->where('id', $uid);
	        		$this->db->update->('users',$data);

	        	return true;



	        }

        else
        {
        	
        	return false;

        }

    }