Can't upload images in Codeigniter - image

Question

I have a problem with upload images in Codeigniter, when I add a new image an error show ( You did not select a file to upload.) I dont know if miss something in my code
this my function controller:
public function upload_img(){
$this->load->model('esthetique_model');
$config['upload_path'] = realpath(APPPATH.'../upload');
$config['allowed_types'] = 'jpg|jpeg|png|gif';
$config['max_size'] = '204800';
$this->load->library('upload', $config);
if ( ! $this->upload->do_upload()){
$error = array('error' => $this->upload->display_errors());
foreach ($error as $item => $value){
echo'<ol class="alert alert-danger"><li>'.$value.'</ol></li>';
}
exit;
}else{
$upload_data = $this->upload->data();
$path = $upload_data['file_name'];
$this->esthetique_model->photo_insert_mdl($path);
echo'<h4 style="color:green">Image uploaded Succesfully</h4>';
}
}
my view :
<?php echo form_open('esthetique/upload_img'); ?>
<div class="modal-body">
<!-- hidden input montinned with class sr-only -->
<div class="form-group"><label class="sr-only" =""></label>
<input type="text" name="idsc" class="sr-only" id="idsc" ></div>
<div class="row">
<div class="col-md-6">
<div class="form-group">
<label for="userfile">Choisissez l'image</label>
<input type="file" name="userfile" id="userfile">
</div>
</div>
<div class="form-group">
<img id="loader" src="<?php echo base_url() ?>asset/images/486.GIF" style="height: 30px;">
</div>
<div class="form-group">
<img id="preview" src="#" style="height: 80px;border: 1px solid #DDC; " />
</div>
</div>
<div class="form-group ">
<div class="input-group">
<div class="input-group-addon">
<i class="fa fa-calendar">
</i>
</div>
<input class="form-control" id="date" name="date" placeholder="Date" type="text"/>
</div>
</div>
<div class="form-group">
<textarea class="form-control" row="3" id="note" name="note" placeholder="Note"></textarea>
</div>
</div>
<div class="modal-footer">
<button type="button" class="btn btn-default" data-dismiss="modal">Fermer</button>
<button type="submit" class="btn btn-primary">Enregistrer</button>
</div>
<?php echo form_close(); ?>
</div>
</div>
</div>
thanks for helping

Answer 1

Try the following (specifying the file input name in your controller):
...
if ( ! $this->upload->do_upload('userfile')) {
...
More information that may be useful: http://www.codeigniter.com/user_guide/libraries/file_uploading.html

Answer 2

I have changed in view
<?php echo form_open('esthetique/upload_img'); ?>
by
<?php echo form_open_multipart('esthetique/upload_img'); ?>
its work now