Tidy your html with PHP Tidy

You don't want to show the ugly page, right. This can be lead by unclosed html tag. I bet, this happens when You let the user input some text into your page.

By that case, you can fix your page by using tidy class in PHP.

Follow this to fix your page;

By default, php is not including tidy class. So you need to install it first by using this syntac;
sudo apt-get install php5-tidy

Restart your Apache service
sudo service apache2 restart

Now, you can use tidy class;
tidy_repair_string($string);

For more detail, you can visit
http://php.net/manual/en/book.tidy.php