<?php $txt=$_GET["id"]; $n=strlen($txt); echo substr($txt,0,3); echo substr($txt,$n-3,3); //  LV 1 if($n!=18) {   echo "FALSE";   } else {   echo substr($txt,($n+1)/2,2);    // LV 2   $con = mysql_connect("localhost","peter","abc123");   mysql_query("CREATE DATABASE ID",$con);   INSERT INTO ID     VALUES ("$txt");    // LV 3   echo SELECT column_name(s) FROM ID;  // LV 4 } ?>