Common validations

<?php

$url = 'http://sub.site.com/';  
if( filter_var($url, FILTER_VALIDATE_URL) ){  
	echo 'valid uri';  
}  

$email = 'sub.name@gmail.com';  
if( filter_var($email, FILTER_VALIDATE_EMAIL) ){  
	echo 'valid email';  
}

// http://fr2.php.net/manual/fr/book.filter.php
// http://fr2.php.net/manual/fr/filter.examples.sanitization.php

?>