PHP filters HTML and other dangerous codes submitted by forms, PHP filters form submissions_PHP tutorial

//get post data
function PostGet($str,$post=0)
{
empty($str)?die('para is null'.$str.'!'):'';

if( $post )
{
If( get_magic_quotes_gpc() )
{
Return htmlspecialchars(isset($_POST[$str])?$_POST
[$str]:'');
}
else
{
Return addslashes(htmlspecialchars(isset($_POST[$str])?
$_POST[$str]:''));
}

}
else
{
If( get_magic_quotes_gpc() )
{
Return htmlspecialchars(isset($_GET[$str])?$_GET[$str]:'');
}
else
{
Return addslashes(htmlspecialchars(isset($_GET[$str])?
$_GET[$str]:''));
}
}
}

function uhtml($str)
{ 
$farr = array(
"/s+/", //Filter excess blanks
//Filter