char detection "PHP"

// sunjester
// 2008
// www.mrsunjester.info
function clean($string) {
$badChars = array("","\"","<",">",".",",","!","@",
"#","$","%","^","&","*","(",")","_",
"-","=","+");

$length = strlen($string);

for($i=0;$i<=$length;$i++) {
$curChar = substr($string,$i,1);

for($j=0;$j<=$length;$j++) {
if($badChars[$j] == $curChar) {
die("string is bad! (error at char: $j)");
}
}
}

return $string;
}

// example usage
//echo clean("!sunjester");
//echo clean("sunjester");
?>