Uploading image/file by creating a directory on the server in yii

$model->attributes=$_POST['Vehicle'];
$model->tax_document=CUploadedFile::getInstance($model,'tax_document');
$model->mot_document=CUploadedFile::getInstance($model,'mot_document');
$model->image=CUploadedFile::getInstance($model,'image');
$model->save();
if($model->save())

   $path="document/vechicle/";
if(!file_exists('document/vechicle/'.$model->id)){
mkdir('document/vechicle/'.$model->id, 0777,true);
chmod('document/vechicle/'.$model->id, 0777);
}
if ($model->tax_document){
$model->tax_document->saveAs('document/vechicle/'.$model->id.'/taxt'.$model->tax_document);
}
if ($model->mot_document){
$model->mot_document->saveAs('document/vechicle/'.$model->id.'/mot'.$model->mot_document);
}
if ($model->image){
$model->image->saveAs('document/vechicle/'.$model->id.'/img'.$model->image);
}
$this->redirect(array('view','id'=>$model->id));