Put a action url in your form as shown below :
<form role="form" action="<?php echo $this->getUrl('modulefrontname/index/save'); ?>" method="post" autocomplete="off" id="form-validate-payment" enctype="multipart/form-data">
<?php echo $this->getBlockHtml('formkey')?>
<div id="form_div">
<label>Title</label>
<input id="title" type="text" name="title" />
<br /><br />
<label>File Name</label>
<input type="file" id="file_name" type="text" name="file_name" />
<br /><br />
<label>Content</label>
<input id="content" type="text" name="content" />
<br /><br />
<label>Status</label>
<input id="status" type="text" name="status" />
<br /><br />
<input id="add_button" type="submit" value="Add" />
</div>
</form>
Then create save action in indexController as shown below:
public function SaveAction() {
$postdata = $this->getRequest()->getPost();
if($postdata){
if (isset($_FILES['file_name']['name']) and (file_exists($_FILES['file_name']['tmp_name']))) {
$uploader = new Varien_File_Uploader('file_name');
$uploader->setAllowedExtensions(array('jpg','jpeg','gif','png'));
$uploader->setAllowRenameFiles(false);
$uploader->setFilesDispersion(false);
$path = Mage::getBaseDir('media') . DS;
$uploader->save($path, $_FILES['file_name']['name']);
$filename = $_FILES['file_name']['name'];
}
$model = Mage::getModel("test/test");
$model->setData($postdata);
$model->setFileName($filename);
$model->save();
}
$this->loadLayout();
$this->renderLayout()
}