Unique Number Sequance

uns.php

<?php
$g = null;
function generate_unique_name(){
  global $g;
	if(is_null($g)) {
		return $g = (((rand()*rand())+rand()));
	}
	
	return ++$g;
	
}

echo generate_unique_name();
echo "<br />";
echo generate_unique_name();
echo "<br />";
echo generate_unique_name();
echo "<br />";
echo generate_unique_name();
echo "<br />";
echo generate_unique_name();

?>